You will also typically have the option to simply opt out, although this is getting less rare.
I think my point is that there are typically still many options, but the best options are controlled by few players.
It's a fake choice, because they carry mutually exclusive catalogs, and entertainment choice is not particularly substitutable (e.g. if I want to watch "Star Wars" and it's not available on services I'm subscribed to, I'm not going to be satisfied with all the rich selection of things they carry that is still not "Star Wars").
Lots of that in the economy, that's where the most money seems to be made. Smartphones are my go-to example: plenty of nearly identical options to choose from, choice entirely set up by vendors, with little to no way of users to voice their feedback. A supply-driven market. You get to choose from what's made available, not what is possible.
Saying entertainment is not substitutable is kind of crazy. It is very rare that I will only ever want to watch one specific thing, and if that happens, I have the choice to rent it, or buy it or pay for one month of a service. To me as a consumer...that great.
The market for smartphones is mostly driven by lack of options in OS, not hardware. Each of the big players offer plenty of hardware choices at different price points. But if you don't like the OS, harder to get away from that. Competing on OS is very difficult though.