Why a query takes too long in statistics thread state in AWS Aurora MySQL?

The following query execution too long in statistics state and I couldn't figure out why. DB engine - 5.7.mysql_aurora.2.07.2 DB Size - db.r5.4xlarge Sample Query Profile output

+--------------------------------+----------+
| Status                         | Duration |
+--------------------------------+----------+
| starting                       | 0.000023 |
| checking query cache for query | 0.000155 |
| checking permissions           | 0.000009 |
| checking permissions           | 0.000002 |
| checking permissions           | 0.000003 |
| checking permissions           | 0.000002 |
| checking permissions           | 0.000009 |
| Opening tables                 | 0.000035 |
| init                           | 0.000102 |
| System lock                    | 0.000035 |
| optimizing                     | 0.000004 |
| optimizing                     | 0.000003 |
| optimizing                     | 0.000011 |
| statistics                     | 0.224528 |
| preparing                      | 0.000030 |
| Sorting result                 | 0.000017 |
| statistics                     | 0.000041 |
| preparing                      | 0.000013 |
| Creating tmp table             | 0.000023 |
| optimizing                     | 0.000013 |
| statistics                     | 0.064207 |
| preparing                      | 0.000035 |
| Sorting result                 | 0.000025 |
| statistics                     | 0.000098 |
| preparing                      | 0.000018 |
| executing                      | 0.000011 |
| Sending data                   | 0.000007 |
| executing                      | 0.000003 |
| Sending data                   | 0.000251 |
| executing                      | 0.000007 |
| Sending data                   | 0.000003 |
| executing                      | 0.000002 |
| Sending data                   | 0.000526 |
| end                            | 0.000007 |
| query end                      | 0.000013 |
| removing tmp table             | 0.000007 |
| query end                      | 0.000004 |
| closing tables                 | 0.000003 |
| removing tmp table             | 0.000004 |
| closing tables                 | 0.000002 |
| removing tmp table             | 0.000005 |
| closing tables                 | 0.000002 |
| removing tmp table             | 0.000004 |
| closing tables                 | 0.000010 |
| freeing items                  | 0.000050 |
| storing result in query cache  | 0.000007 |
| cleaned up                     | 0.000004 |
| cleaning up                    | 0.000017 |
+--------------------------------+----------+

Query

select xo.ITEM, xo.VALUE
from (
         select pi.ITEM, pi.ITEM_GROUP, pi.VALUE
         from TABLE_2 pi
                  inner join (select max(ps.EXPORTED_DATE) as max_expo, ps.ITEM
                              from TABLE_2 ps
                                       inner join (
                                  select max(pp.EFFECTIVE_DATE) max_eff_TABLE_2, pp.ITEM
                                  from TABLE_2 pp
                                  where pp.EFFECTIVE_DATE  SHOW INDEX FROM T1;
+-------+------------+--------------+--------------+----------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| Table | Non_unique | Key_name     | Seq_in_index | Column_name    | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment |
+-------+------------+--------------+--------------+----------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| T1    |          0 | PRIMARY      |            1 | CUSTOMER_ID    | A         |     3297549 |     NULL | NULL   |      | BTREE      |         |               |
| T1    |          0 | PRIMARY      |            2 | ITEM           | A         |   687374784 |     NULL | NULL   |      | BTREE      |         |               |
| T1    |          0 | PRIMARY      |            3 | EFFECTIVE_DATE | A         |  1314196480 |     NULL | NULL   |      | BTREE      |         |               |
| T1    |          1 | t1_ix_item   |            1 | ITEM           | A         |     2151649 |     NULL | NULL   |      | BTREE      |         |               |
+-------+------------+--------------+--------------+----------------+-----------+-------------+----------+--------+------+------------+---------+---------------+

Table 2

mysql> SHOW INDEX FROM TABLE_2;
+-------+------------+-----------------------+--------------+----------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| Table | Non_unique | Key_name              | Seq_in_index | Column_name    | Collation | Cardinality | Sub_T2rt | T2cked | Null | Index_type | Comment | Index_comment |
+-------+------------+-----------------------+--------------+----------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| T2    |          0 | PRIMARY               |            1 | ITEM           | A         |           1 |     NULL | NULL   |      | BTREE      |         |               |
| T2    |          0 | PRIMARY               |            2 | ITEM_GROUP     | A         |       14265 |     NULL | NULL   |      | BTREE      |         |               |
| T2    |          0 | PRIMARY               |            3 | EFFECTIVE_DATE | A         |    63663076 |     NULL | NULL   |      | BTREE      |         |               |
| T2    |          0 | PRIMARY               |            4 | EXPORTED_DATE  | A         |    62464764 |     NULL | NULL   |      | BTREE      |         |               |
| T2    |          1 | t2_ix_item_expo       |            1 | ITEM           | A         |      115823 |     NULL | NULL   |      | BTREE      |         |               |
| T2    |          1 | t2_ix_item_expo       |            2 | EXPORTED_DATE  | A         |    13766454 |     NULL | NULL   |      | BTREE      |         |               |
| T2    |          1 | t2_ix_item_eff_date   |            1 | ITEM           | A         |      115823 |     NULL | NULL   |      | BTREE      |         |               |
| T2    |          1 | t2_ix_item_eff_date   |            2 | EFFECTIVE_DATE | A         |    13766454 |     NULL | NULL   |      | BTREE      |         |               |
| T2    |          1 | t2_ix_item_eff_ig     |            1 | ITEM           | A         |      115823 |     NULL | NULL   |      | BTREE      |         |               |
| T2    |          1 | t2_ix_item_eff_ig     |            2 | EFFECTIVE_DATE | A         |    13766454 |     NULL | NULL   |      | BTREE      |         |               |
| T2    |          1 | t2_ix_item_eff_ig     |            3 | ITEM_GROUP     | A         |    68216912 |     NULL | NULL   |      | BTREE      |         |               |
| T2    |          1 | t2_idx_effective_date |            1 | EFFECTIVE_DATE | A         |       79406 |     NULL | NULL   |      | BTREE      |         |               |
+-------+------------+-----------------------+--------------+----------------+-----------+-------------+----------+--------+------+------------+---------+---------------+

According to this: https://dba.stackexchange.com/questions/55969/statistics-state-in-mysql-processlist I checked the innodb_buffer_pool_size.

mysql> SHOW VARIABLES LIKE "innodb_buffer_pool_size";
+-------------------------+-------------+
| Variable_name           | Value       |
+-------------------------+-------------+
| innodb_buffer_pool_size | 96223625216 |
+-------------------------+-------------+

In EXPLAIN output rows are minimal (Depends on the Item count in the query. If Item count is 10, the number of rows were 20). Even though the row counts are minimal why the query takes too long in statistics state?