JSONB vs JSON for column-oriented data in PostgreSQL

I am processing data tables with varying numbers of columns and rows, represented by JSON documents with one array per column. The format of a document is

{
    "column_1": ["value_1_1", "value_1_2", ..., "value_1_n"],
    "column_2": ["value_2_1", "value_2_2", ..., "value_2_n"],
    ...,
    "column_m": ["value_m_1", "value_m_2", ..., "value_m_n"],
}

The number of columns m is typically in the lower tens, while the number of values n lies in the lower millions. Values are either small integers or short strings, and individual data tables stored as text files are 100-200 MB in size. Documents are stored in a jsonb column in PostgreSQL:

Table "data"
             ************

    Column    |  Type   | Nullable 
--------------+---------+----------
 dat_id       | integer | not null
 dat_document | jsonb   | not null

Documents are typically served "as is" to an application or with a simple filter, e.g.,

select col2, col7, col9
from (
        select jsonb_array_elements(dat_document->'column_1') as col1,
               jsonb_array_elements(dat_document->'column_2') as col2,
               jsonb_array_elements(dat_document->'column_5') as col7,
               jsonb_array_elements(dat_document->'column_9') as col9,
        from data
        where dat_id = 20
    ) as sub
where sub.col1::text like '%@yahoo.com';

The documents are stored as jsonb following recommendations from the [PostgreSQL documentation](https://www.postgresql.org/docs/current/datatype-json.html) , however, when using the simpler json type instead in the table *data*, I do not notice a significant drop in execution time for simple queries as the one above. On the other hand, my documents seem to take roughly 50% more disk space according to pg_column_size on the same document as jsonb vs json. Is there any advantage of storing my documents as jsonb instead of json in this case?