Ideas I’ve come across:
More autonomy for smaller groups of people with technology-assisted methods for direct governance. (As in, city-level referendums on all sorts of issues.)
Radical transparency, which keeps people honest. (Requires caution in its interplay with civil liberties.)
Combining these first two, could you keep a public database to show who’s voted in each election, to increase civic engagement?
Universal basic income. (But what do people do in their free time, instead?)
As you said, AI. For example, autonomous vehicles could improve the lives of everyone with a commute and reduce the number of cars on the road. AI will also displace millions of people from their jobs, though, so its implementation has to be done thought fully.
“Off the grid” electricity — for example with solar roof tiles — combined with a revolution in local food production. (There’s still a big tech opportunity for successfully connecting consumers with their local CSAs and farmers.)
Granted, most if not all these ideas address already-rich societies. But it’s worth discussing their merits to see what other ideas might arise.
Paul Mason’s Postcapitalism is an interesting primer on the topic.