Similar setup: I use Google Fi with a Google Pixel 3 phone, and I will buy the Purism Librem 5 phone.

I get ~5 calls/day that are legitimate calls with unknown numbers, and ~10 calls/day that are spam robocalls. I use Google screening and it works reasonably well; I would much prefer to have a telco do the screening automatically.

I use ~10-20GB of data per month, mostly for video calls, mostly for business, mostly via Signal, Slack, Zoom.

Feel free to PM me if you would like more. Contact info is in my user link.