I have the standard Firefox for iOS, and the only security setting I see that might be related is “Enhanced Tracking Protection”, which is set to standard. I would assume that should allow basic cookies for persistent login though. I wonder if there’s something about Lemmy that is causing it to be detected as some kind of ad tracking thing?
I agree that this is probably the inevitable end result of the proliferation of the technology. The journey society is going to have to take to get to that point is going to be pretty uncomfortable though I think.