In Chrome there's an icon you click to switch. Honestly, if someone would create a FF extension that was just that, it would probably cover 90% of what's considered superior in Chrome.
That's on my main/personal profile.
I have separate profiles for work stuff, one for each client or organisation I work with. On those, I only access sites that are relevant to the organisation, and I have a lot fewer protections. I keep long sessions, I leave cookies in place, etc. It's a lot more convenient that way.