ISP “choice” is mostly a meme, yeah.
But depending on local rules, you can sometimes route around the monopoly: trench your own last-mile (at least on private land), do a neighborhood co-op, connect buildings, etc. It’s sometimes expensive and you’ll hit permits/right-of-way bureaucracy, but it’s totally doable if you’ve got a few (rich) friends or a business willing to back it.
“the conduit is full” is often just BS and a super convenient excuse for incumbents to block competition indefinitely.
Romania is a good example of what happens when lots of small operators aggressively wire dense apartment blocks: brutal competition, low barrier to entry, and suddenly everyone has insane internet.
If digging is blocked, wireless works too. Point-to-point links, WISP stuff, even satellite. The main thing is: you don’t necessarily need your local ISP as your upstream, you just need a path out.