Why do steaming services think they have a captive audience and I'm not going to ditch all of them with the crazy influx of annoying ads?

Bcs they act as a monopoly in regards to alternatives.

They only slightly intend to compete against each other but pretend nothing else exist (pirates, or people just shifting towards other forms of entertainment).

And they are ofc in cahoots in the sense that their common goal is to normalise paying several hundred moneys per month for streaming services and have the streaming service full of ads regardless.
So in that sense they will not compete but back each other up.

Like land owners/landlords, their main goals are completely aligned.

And that is how 'market disruptions' actually work - its not to offer a new service to the end user (like Uber-ish services are the same as taxi services from the perspective of users), it's to undercut the existing regime with lower prices whilst living on capital given because of the promise that once the old regime is gone they can crank up the prices & actually profitable (we are actually just at this stage right now - watch how much monthly fees are gonna go up in just a few years).

Goal/end stage:
Users are gonna be glued to their ad-ridden TVs just the same as boomers but far better monetised (watching TV is gonna be expensive).