Sar network monitoring seems inaccurate?

I've been monitoring my system using sar. I recently came across some interesting data: These are the stats for one of my Calico network devices... it seems to spike between ~0.2 Gbps and 20 Gpbs. The spikes are huge. We use these devices for Docker container networking.

12:00:01 AM     IFACE   rxpck/s   txpck/s    rxkB/s    txkB/s   rxcmp/s   txcmp/s  rxmcst/s
06:30:01 AM cali3bdaf00a84e 140696.72 150995.79  14960.45 2318047.28      0.00      0.00      0.00
06:40:01 AM cali3bdaf00a84e   1151.92   1264.66     81.12  21359.03      0.00      0.00      0.00
06:50:01 AM cali3bdaf00a84e 142858.42 153379.32  15114.04 2359706.82      0.00      0.00      0.00
07:00:01 AM cali3bdaf00a84e   1050.13   1162.73    136.67  20572.62      0.00      0.00      0.00
07:10:01 AM cali3bdaf00a84e 144932.62 155685.65  15322.14 2400295.98      0.00      0.00      0.00
07:20:01 AM cali3bdaf00a84e   1139.16   1251.25     80.36  20570.52      0.00      0.00      0.00

Same for my eth0 device, it spikes up to ~75 Gbps

12:00:01 AM     IFACE   rxpck/s   txpck/s    rxkB/s    txkB/s   rxcmp/s   txcmp/s  rxmcst/s
06:30:01 AM      eth0 10379825.81 5627209.54 10868448.25 8197353.75      0.00      0.00      0.00
06:40:01 AM      eth0  30695.55  14409.05  30708.83  27764.83      0.00      0.00      0.00
06:50:01 AM      eth0 10437914.98 5649581.74 10928787.81 8240375.35      0.00      0.00      0.00
07:00:01 AM      eth0  31251.21  15185.05  32729.30   8387.41      0.00      0.00      0.00
07:10:01 AM      eth0 10497803.58 5682599.52 10989315.11 8261565.31      0.00      0.00      0.00
07:20:01 AM      eth0  30306.80  16156.03  29500.73  11821.10      0.00      0.00      0.00

These numbers don't agree with the GCP App Engine network monitoring in the GCP UI that shows a maximum of 100MB/s or so. **Are the sar network metrics that it reports accurate?** **What could cause this tool to report different metrics than the GCP network monitoring tool?**