Yeah, but it doesn't do anything special. Sure, it's pretty much guaranteed to work for the Deck, but other than that you don't get anything out of it that you can't get elsewhere. There's no special sauce that Valve puts in. The only thing they put in that's special is Proton, except the contributions are open source and freely available everywhere.

All distros are supported by some group. Valve isn't particularly special in that, except it isn't their specialty like other distro maintainers.

If you're switching to Linux to avoid a huge corporation then you should do that —and Valve is a pretty damn large corporation. Sure, they're doing good things now, but people would have said the same thing about MS at some point in time. Don't build them up into something else. Use the best option, not just following some brand loyalty for no good reason.