I never understood why people were so autistic about their hatred of the new Star Wars movies until seeing the Foundation Trailer and reading about the work.
There's an insane amount wrong with Apple's Foundation; it's immensely disappointing that what we've seen indicates it will be normie-fodder bland CGI shit and basically will ignore the source material for the writer's own spergry. Plus the insertion of politics will only be a determent to a work like Foundation.
I want to see Weenis getting dabbed on by Salvor Hardin through cunning and words, or Hobor Mallow using the power of "lods emone" to strangle Korell FFS, not Gale Dornick and Hari Seldon's shooty adventures through the Empire. Hell, the opening shot with fem-Dornick getting to see Trantor from space demonstrates how little they actually read the books or gave a shit about them.
People said Dune was impossible to adapt into a movie but I always disagreed with that notion. I do adore the 1984 movie though, but I'm not blind to how terrible it is as a straight adaptation of the source material. In my opinion, if you want a series that cannot be adapted to a movie, it would be Foundation.
Speaking conventionally, Foundation does not have a plot. At least not a singular, contiguous one. It definitely does not have a main character. The important characters throughout each story are almost always unrealted to each other as well, so you can't pull any bullshit with identical descendants. The series also lacks a singular villain or villanous faction. Technically if you count regime chages as a change in faction, there isn't even one protagonist faction that stays in power. (The Foundation is only a country, its internal factions change and evolve as time goes on; from the Encyclopedists, to the Merchants, to the Mayoral Dynasty, etc). You can't even reuse sets and props because of the immense time span between segments; you'd have to dress at least interiors differently depending on the era.
The only way I could see Foundation coming anywhere near being faithfully adapted would be to turn it into a sort of anthology show. Episodes about an hour each, with only three at most devoted to each segment of the story. I'd actually dare say that almost every segment of the story can be boiled down into only a single episode, with the exception of the longer ones like the Mule plotline and the Second Foundation plotline.
More importantly though the show lacks all of the draws that Star Trek, Star Wars, Bablyon 5, even Known Space and such have made people accustomed to. There are almost no space battles, no sword duels, no bombastic Flash Gordon-esque supervillains, nothing. Just politics and the occasional detective plot, with science fiction trappings. You could hypothetically film the entire series in one room with a few people talking, boring as that would be. There's an audio drama out there that does exactly this. People like me would be fine with that, but modern audiences would be bored to tears most likely.
More than anything else though the series has no ending, and consensus is that Foundation and Earth is widely disliked. There's not really a good solution to this.