You're not locked into their service at all, you can use Steam VR content on it and you can run arbitrary .exes on it.

It's less of a walled garden than tablets, smartphones or consoles which almost everyone just seems fine with.

We're finding out the cost, now, of the extreme centralization of these platforms, especially caused by their device-locked app stores. Doubling down on the idea because people "seem fine with" it is a bad idea, especially now that we have hindsight. It's no mistake that the big innovation of the era, cryptocurrency, is happening largely outside of all the platforms you listed.

Also, I know that you can run SteamVR apps - I develop a VR game with hundreds of thousands of dollars in sales on Steam, but I've been locked out of the Oculus store for...unknown reasons? Someone behind the black box must've made a decision to block it.

We were always fine with it, PCs were the outliers.

I never had any big issue having to deal with Spectrums, C64, Atari, Amiga, PC and their exclusives.

Likewise with all the game consoles I've owned.

I think the lock-in is more regarding Oculus-exclusive content. My understanding is the community has mostly gotten those working on other headsets by now, but Oculus itself certainly hasn't helped.