It's not necessarily that I see that many reasons to be optimistic, as that I don't want to just give it up as a hopeless cause... and I don't have any brilliant ideas as to the solution, I generally just approach it from a 'whatever remains after we've discarded the absolutely unacceptable or impossible solutions has to be the least unworkable solution' perspective.

So, no solutions in which either side gets the entire territory and the other one is just exterminated or expelled. No permanent apartheid/segregation 'solution'. No utopian fairy tale in which both sides just magically forget about all their grievances and share the land peacefully from here on out.

Which leaves us with some form of a trade off in which Israel gets hard security guarantees and improved relations with its neighbours, in exchange for major concessions to enable the Palestinians to live their lives in peace and freedom. I wouldn't be against some kind of bi-national confederacy / federal state, but it seems even less likely than a two state solution, so more likely the latter. And those Israeli concessions can and probably should include money, but it's inevitable that they would also include territory - certainly large parts of its illegally (in the eyes of nearly all of the world) occupied territories, possibly also parts of its internationally recognized territory, in exchange for being allowed to keep some of its occupied areas which would be extremely impractical to give up.

I think money would be an important part of any solution, but still it couldn't be the decisive part. And I can't see several million Palestinians just agreeing to become Saudis or Egyptians - nor would those host countries just take them.

Mind you, there are also millions of Palestinians still in the neighbouring countries, like Lebanon and Jordan, who've never been fully integrated or given full rights there, in part because their host countries didn't want that but also in part because they themselves didn't want to give up on their dream of returning. For those, I really don't see how any large-scale return would ever be possible, so those still would need to be settled permanently and with full citizenship in the other Arab countries.