I still use Firefox and continue to have great results. It's basically the only semi-popular browser still out there that isn't based on Chrome. If you use a Chromium-based browser, even something like Edge or even Brave, you are still supporting the Google Chrome monopoly. Chromium is "open source" but Google still very much controls the direction of development, and people still end up steered toward Chrome.
The reason why Firefox occasionally has issues with certain sites is because website developers get lazy and simply program their site for Chrome rather than using actual web standards. As long as it works with Chrome, they don't care if other browsers work correctly or not. Sort of like 15-20 years ago when every site only worried about Internet Explorer compatibility. Unfortunately this is only getting worse as Chrome solidifies it's monopoly. So the real question is not about what browser you want to use, it's more about how firmly you are willing to allow Google to squeeze your testicles.
Thankfully Firefox still works fine 99.5% of the time, including all of the sites that I care about. Edge is fine for the few remaining sites.
I use Firefox at home, but with Edge now actually being a good browser I think for many people the out of the box experience is great. I occasionally use Edge though when I need to confirm if an issue is due to Firefox or also exist in Chromium. Unfortunately, many web devs only test on Chromium.
At work, I also use Firefox but I also keep Chrome installed because so many users have it and it's nice for being able to use the same browser as they are for troubleshooting their issues or helping them with the GUI, etc.
Chrome and Edge aren't so much browsers as data collection and user profiling vacuums that happen to have web browsing capabilities. Don't let them near you.
Brave with the Momentum dashboard (homescreen plugin) + Extensity plugin to manage your other plugins easily. Though I am getting concerned Brave is quietly backsliding further into monetization angles with the proliferation of Brave commercials appearing on TV and major podcasts for it now - those commercials aren't cheap.
Firefox is fine because at least it's not Microsoft or Google.