If it’s in your systems in an open format it’s yours, if it’s outside your systems or wrapped in some kind of locked format that forces you to go through somebody else’s software it’s de facto theirs.
Due to my own experience in software development with 3rd party solutions from way back, I never adhered to Streaming solutions (even though I was tempted) and always stuck to getting my entertainment in a media format I controlled (legitimately for a long as I could, not so much once even physical media started having DRM) because I was aware that it’s risky to outsource so much control over one aspect of what you do (in this case entertainment) to an entity which, frankly, sees you as nothing else that microscopic fraction of their bottomline.
(The funny bit is that if Netflix would sell me their Series in an open file format that I could download and at a reasonable price, I would have sent lots of money their way, same as I spent lots of money on DVDs and even VHS tapes back in the day. In fact all throughout that period I was doing something like that for games: as soon as I discovered GOG with their DRM-free downloadable installers, I started acquiring all my games by buying them from GOG)
In the fullness of time, my caution seems to have been proven right.
The more services you have depending on a 3rd party which can do whatever the fuck they want, either directly or by changing the rules when the feel like it (i.e. not bound by rules they cannot change, such as root DNS providers are) and then doing it, the less your system is actually self-hosted, IMHO.
For me the whole point of self-hosting is exactly being as independent as possible of 3rd parties that can just fuck you up, be it on purpose (generally for $$$) or because they go bankrupt and close their services.
This is why I’ve actually chosen to run Kodi on my home server that doubles down as TV Box even though I can’t easilly use it from anywhere else (it’s possible but it involves using a standalone database that is then shared, which can only be safelly done through customly setup ssh pipes) rather than something like Plex.
It’s kinda funny to see people into self-hosting still doing the kind of mistake I did almost 3 decades ago (fortunatelly in a professional environment) of trusting a 3rd party to the point of becoming dependent on them and later getting burned when they abused that trust, and which led me to avoid such situations like the plague ever since.
Mind you, I can understand if people for whom self-hosting is not driven by a desire to reduce vulnerability to the whims of 3rd parties (which includes reducing the risk of enshittification) and is instead driven by “waste not” (for example, bringing new life to old hardware rather than throwing it out) or by it being a fun challenge, don’t really care to be as independent as possible from such 3rd parties.