I think those other clubs that initially participated in the ESL, together with us, Madrid and Juventus the three remaining ones were all going after the promised $ potential, more than anything else. Let's be honest, if clubs ditch the UEFA and go for the ESL gang, they are looking for money.
I don't think Florentino and Laporta etc. had the goal of creating a more balanced and fairer playing field in mind when they pushed for the ESL then or now. I don't think the ESL will necessarily handle issues such as state-own clubs or the FFP much better than UEFA (they are not going to turn away City, PSG and New Castle etc.)
All those other issues aside, fundamentally I question whether the ESL will bring in more money as those clubs were looking for, basically its viability. Also what is the price to pay. The funds behind the ESL will be looking for big payouts. Perhaps it is like the CVC deal model, awarding participating clubs a lot of money up front and then provide resources to help the ESL grow? I just don't know.