He's left to focus on his ideas for making money with Bitcoin. Compared to crypto, Twitter is just not very exciting.
I don't know him personally so I could certainly be mistaken, but from listening to him speak/write and based on his charitable giving I don't get the impression at all that Jack is motivated by riches. I think he is genuinely interested in Bitcoin as a tool for advancing humanity. I also don't get the impression he is interested in 'crypto'. I guess it remains to be seen though.
Well, if you have more riches, you can do more charitable giving, so I don't see why he would not be motivated by the possibility of more riches.