

Absolutely. It’s also an immense amount of work to get a platform up to a competitive standard with Steam; I’m not sure a small company will ever be able to catch up in any short term time frame.
But stores like Fanatical, GreenManGaming, GameBillet, etc. have the better idea of just being stores that focus on getting customers better deals. They don’t even attempt to edge onto Steam’s turf because a storefront can’t compete with Steam, nor can a half-baked launcher.
Reality is that Valve has functionally a 20 year head start on any company that wants to try and edge in on their turf. So it can’t be done just to get a cut of sales because you’re not going to have the follow-through to build the user base if that’s your reason.

I see your point, but I also think that Steam is so much more than what your example gives. In your case, Steam also has Instagram built in, it has photography forums, it has low-level interfaces to standardize hardware control across multiple camera brands and types, it has a body & lens store, it offers additional software to aid in photo editing, and… and… and…
It’s really an impressive accomplishment what Valve have done with Steam and the hardware/software in its orbit. And that’s not even mentioning all the work that they’ve poured into the open-source community to make Linux a viable gaming platform. Yes, it serves them all in the end, but little of it is easy and it’s all taken a lot of work over the years.