I agree the "e2e-encrypted email" bit is mostly marketing until GMail keeps its dominion on the market, which might be still for a very long time, but that's entirely up to us. I have some contacts who use Proton and some not, in the same way I have contacts who use Signal and some who don't. It doesn't have to be a full victory for me to make the switch worth it, even if just a minority of the users, the ones that I care about, do jump on the wagon I consider that a full personal victory.
I really haven't felt the Proton marketing push either... actually quite the opposite! I found out they have now a Meet application by chance even after so many years being a paying customer. Not sure what "bridge" you're talking about, unless you refer to accessing encrypted mails via IMAP, which I don't do so I don't care, webapp or `brew install protonmail` or installing the iOS apps do the trick for me and I don't see how that can be a win for GMail, it's just a different app which looks similar, no? AFAIK you can use all Proton applications from any browser, the ones I use (mail, calendar and meet) definitely work on Firefox for me.
About the domain ragpull fear... that sounds very unlikely? I mean, unless you choose a very esoteric TLD the probability of Google automatically banning your account seems to be a much much higher one? but still, if you switch to another provider you don't really need to setup a fancy domain, you can still setup GMail forward etc to the new @pm.me address or else. By the way, the "receive wildcard domain emails" is also an opt-in in Protonmail, you don't get it enabled automatically, so shouldn't be a blocker in itself.
Probably I'm a much simpler minded person, my heuristic goes somehow like "do I hate the company? yes -> is there a decent alternative? -> yes -> use it"