I agree with what you say about the European Super League - initially aghast at the idea, but now for it to due to how non-competitive the league is becoming. I do get that the proper fans of the big clubs are generally against leaving domestic league though.
I was wondering if the concept of a new club franchise model (no relegation) for a super league could work. Instead of Manchester United and City having teams in a Super League, you'd have one new Manchester franchise. Similar for London, Liverpool, Madrid, Barcelona, Milan, Rome, Munich, etc.. Chuck a couple of Saudi Teams in for good measure.
The very top players would then be contracted full time to these teams with no FFP so they can knock themselves out. The domestic leagues in the countries where there is a franchise would have to sign up to stricter FFP rules - transfers capped to £50m and wages to £100k/year say.
May be difficult to establish initially and the EPL would be up in arms of course, but something needs to be done before the league ends up like Scotland.