The thing holding it back is some kind of central authority that can process micropayments with significantly less friction and overheads.
Even better if people can accrue credit in some way that isn’t just paying fiat currency in, because we live as a privileged class to have disposable income that is essentially in escrow.
There are a lot of downsides to ads, but it is the most successful micro payment mechanism we have. It is also the most successful online business model we have.
Be careful what you wish for, I guess.
Attention as a replacement for hard cash. Hmm... So, how to control its spending as a consumer - that's the question. We're like natives selling land for glass beads. Can we omit ranting and make that a technological problem somehow?