I'm sure City/PSG caused the other clubs some consternation, but the big draw for the English clubs is financial. The ability to have more say on league matters (proportional to the money brought in) has probably been a source of frustration. You look at the rest of the league's attitude towards things like 5 subs or a winter break, and you can see what the response would be if clubs like Liverpool or Manchester United wanted more freedom to sign their own deals to stream some matches, or to have more control over how TV money is distributed, or to have more control in general given the financial implications (like CL qualifying and the money that comes with that).
Don't know if this will lead to anything, but it's no surprise the big clubs are constantly talking about this closed shop where they get to make the rules. It's money and selfishness unfortunately. The UK press often likes to pin it on foreign ownership (especially American), but it's not like it doesn't apply to British owners also. You look at Karren Brady talking about null and void last year (when West Ham were fighting relegation) and Steve Parish talking about not bailing out lower league clubs, and it's the same concept of selfishness as those have serious financial implications. The rest of the clubs in the league also want control over financial matters, which makes sense from their perspective. The top clubs see them as benefiting from the top clubs' appeal and success without letting the top clubs have enough say. The rest of the clubs see the top clubs as selfish and constantly wanting to close doors.
It never had to get to this point, but it's hardly surprising that we're here.