Up until a couple of weeks ago, I was using Mosaic, but it's starting to showing its age a bit too much. 🙂
Seriously, I use Safari most of the time on the Mac, with Firefox always available for the too many websites that don't work properly in Safari. I only use Chrome to watch YouTubeTV, as it seems to play better than the other browsers. I've tried Opera and Brave, but they just don't do much for me. On Windows, which I really only use for gaming, I use Firefox, and on my iPhone it's Safari and occasionally DuckDuckGo, if I want to be a little more careful about privacy. I'm looking forward to trying the Mac version, for that same reason, but alas am just on the wait list. Finally, while I don't it much since retiring, I turn to Firefox for Linux.
So why Safari, if has so many problems with some web sites? I like the simple integration with Mac/iPhone browsers, sharing passwords, bookmarks, reading lists, history, etc, without yet another online account knowing those things.