Still use Chrome at work and it's a good way to keep them separate. I'll even use Safari if I want to log in as different users or test rendering. I try not to use more than one window per browser, it's easier to switch between browsers than figure out which window is which context of the same browser.
I find Chrome just an overall better experience to use. I am kind of a stickler for UI and to me, Brave's and Opera's are a bit clunky even though they're based on the same VM.
As for Firefox, the experience does not have far to go in my opinion but I have had a lot of issues with memory leaks and crashes lately so I switched back to Eloston Chromium.
on Android, I've settled for brave. js controls suck, but at least no ads.
on iOS, safari is good enough for basics, i rarely do more on iOS.