A24 seems to have hitched their wagon with Apple. Neon is doing a lot of co-distributions with Hulu. United Artists is led by Annapurna and MGM, the former is basically a private arts fund and the latter is looking to sell itself eventually.
Indie distributors will continue to exist, but the business is tough and there are alot of distributors throughout history that eventually went under: FilmDistrict, Relativity, Polygram, MGM for a while, New World Pictures, AVCO Embassy Pictures, going all the way back to Monogram & Republic Pictures in the 30s.
Idk how well a bespoke streaming service would work, there are already services like Mubi, Sundance Now and Criterion that do that and they're not really the biggest services. I think indie distributors will have a future basically selling and co-distributing with streamers like Hulu and Nettles, yah; they help subsidize the big streamer's content budgets by ponying up cash for big Sundance titles and they basically do free curation for them.