You can own certain Steam games as much as you can own them on GOG, which is to say it's completely up to the publisher/devs. https://www.pcgamingwiki.com/wiki/The_big_list_of_DRM-free_games_on_Steam

But I can play them without Internet (mostly).

Steam isn't perfect. But it's the best we have for now. And the trend currently is only getting worse.

The thing is that Steam doesn't have a history of shutting down a significant fraction of games they have available by themselves. Hence people don't criticize them.

Also you can (not saying that you should, I personally don't trust Gabe) put some tust in a private owned company if you trust the owners.

In case of public companies they are forced by law and major shareholders into making shortsighted decisions and prioritizing profit only.

Don't you dare slander Lord Gaben 😭😭😭