I've been using Firefox as my main browser to support its decreasing market share, alongside Safari for development and Ungoogled Chromium when things are unexpectedly broken in Firefox (due to strict privacy settings most of the time). I'm considering dropping Firefox because I don't want to deal with updating about:config anymore to remove ads, telemetry, etc. The other two browsers just work for me.
Edit: this is not completely true - I enabled Private Relay (Safari only) and installed uMatrix and uBlock Origin on Chromium, but that's about it.