Banks have banded together to create Zelle for mostly instantaneous payments for individuals. As far as transactions between individuals, moving money quickly is a solved money. As for moving money from individuals to businesses, taking a long time gives customers more "float" and more time to earn interest, and it is a feature not a bug.
There are other issues to consider in the payments world. For example, I may not want my payment data to be used for marketing purposes[1] or have my payment processor block my steam purchases[2]. I'm skeptical that Stripe will deliver on those gaps though.
