It helps that Valve is privately owned and thus less likely to chase growth over other things.

Hopefully when the current owners age out the new leadership will continue as it is.

With Steam you can basically make your own personal Stadia with the steam link app, no need to re-buy any games again and no need to rely on anyone else's cloud services (as long as you have a decent connection and PC)

I backup all the games I have on Steam locally. If they ever go under, I will get a DRM crack.

I saw something the other day that really struck home on this: for any given software technology you encounter, your best estimate is that it's halfway through its useful lifetime.

I know some TED level influencer had some story about basically everything in mail order catalogs from 100 year ago is still for sale somewhere today, so maybe it's wrong, or maybe software is just more prone to vanishing.

In addition to Steam, I have GOG and Epic linked to my Steam Account, they sync my Steam purchases in their library if the publisher allows.

So I would imagine if Steam did go under, they would all be clamouring to help users transition to their platforms.