For my private use, I am using an older Mac with some memory consumption issues, so until I upgrade, I am using safari because it's the most lightweight, and while the extension support is the smallest of all, at least for very major things you are still covered.
For work, the Mac I am using is way more powerful, and yet I find strange issues. Vivaldi dies if I open more than 60-70 tabs at once but it doesn't even really matter, because all the Chromium based browsers that have said "don't worry, we will keep maintaining Manifest V2" feel like they are on a "danger zone" to me.
And then, I try to use Firefox and while the extension support is the most complete, many times I am finding unresponsive pages (usually tools like Google Meet, which I need to use because of work) or even worse: profile files get messed up and I start getting an error "There was an error, that's all we know" every time I try to log into any service using Google SSO.
So to summarize, at this rate I will have to migrate to Qutebrowser... or Lynx.