I've had first party isolation turned on for possibly a couple of years now (certainly since before the pandemic) and it does break a small number of sites but

I've had first party isolation turned on for possibly a couple of years now (certainly since before the pandemic) and it does break a small number of sites but nothing I particularly care about. Except that one internal tool that I've taken to loading in Chrome :P. I don't recall the last time I had to temporarily disable it to allow something to work.