The screenshot shows traffic volume per destination. I don't see a feature that would require traffic decryption nor any mention of how to install a cert, so I assume no. What would you want traffic decryption for?

"What would you want decryption for?"

Not OP, but here's a Google employee explaining why one would want to decrypt traffic.

https://web.archive.org/web/20220813220108if_/https://medium...

More from F5.

https://www.f5.com/solutions/use-cases/ssl-visibility

Anything wrong with mitmproxy (not a user myself, just curious)

Nothing in particular, although it's UI is quite dated and not very user friendly.