Terraria does not rely on steam features in order to engage with its core functionality. Perhaps you are trying to imply that the error is in the developers having integrated their publishers features into their release in such a way that a hard dependency on the runtime is formed when it shouldn’t be.
This is not a valid argument because whatever calls terraria is making to the runtime should have a fallback in place for when the runtime is not being used. That fallback should be implemented by a small dummy runtime or something. It shouldn’t be on the devs to ensure their single player game works when the publisher’s adware bloated garbage runtime stops working.
If you own a physical cartridge/disk on an old console, you own permanently playable physical copies of the games. No publisher is able to stop you from playing it. It is a permanently usable piece of tangible property which you legally own. This is what people talk about when they say they “own” games. IDGAF if the GoG ToS says I don’t “own” a game if they have no ability to revoke my ability to play it once I’ve downloaded it. It’s as playable as any physical game, for as long as I keep my hard disks intact. This is what it means to “own” a non -service based game, by any sensible definition of the word.
No one here claimed you become, or deserve to become the IP holder of the software. This is just a strawman that you made up because the idea of someone not making the same idiotic purchasing decisions as you personally offends you.
Publishers should not be able to deny you the right to modify the software you downloaded after you downloaded it. If they have a different opinion on the matter then I won’t be a consumer of their services.
It’s all just Stockholm syndrome and copium for you. Maybe one day in your 40s steam will decide to bleed you dry for everything you think your library is worth. They’ll force you to pay a subscription fee just to access single player games purchased many years ago.
And you’ll be able to do nothing about it, because you never own a game unless you buy the holder of the IP. Read your TOS. You buy a licence to use a software and to obtain the necessary data to use it. Nothing more.
Keep defending your abuser though I guess.