Steam Deck

The reason Valve is so heavily investing in Linux is that they know that Microsoft could - in theory - flip a switch and kill their business, especially because Microsoft themselves is a competitor to Valve in the form of Xbox and Gamepass.

It's a defensive tactic, not a money-making venture.

Windows, currently, cannot handle everything Linux can. Linux also has a massive software support advantage, running on vastly more hardware and architectures than Windows does.

Linux has already been given to the masses. People use it every day in super user friendly ways; they just don't realize they're using Linux.

The only reason people use Windows is because they don't choose it. Imagine if every PC sold had a Linux option and a Windows option that cost an extra $100. What do you think people would buy?

The same hardware running Linux will easily outperform Windows (especially at the most common end user tasks like web browsing) by a long shot. In a few days NTFS turns 30 years old FFS (LOL).

Any given hardware accessory will "just work" when plugged in to a Linux PC but Windows will require a special driver that you have to go out and find on your own at the vendor's website that will be bloated AF. It'll also reinstall it if you change the USB port LOL.

I specifically phrased it "could be" as people tend to believe there are 3 preferences, Mac, Linux and Windows. Linux is not one user experience, it could work exactly like your favorite OS. In the face of SteamOS already being a viable option for the average gamer as Valve is basically strong arming it to be, on Steam Deck you're not exactly doing PC gaming any good deliberately installing Windows on it. SteamOS just works.

I also think you're very misguided in thinking it won't have any return to Valve. Microsoft has to be looking at Google Play Store and whatever the Apple Store is called with a lot of envy with how they've managed to lock the entire ecosystem under their stores. This is the end result for Windows as well and its likely anti-competetive clauses are a very bad sign for a company like Valve. Looking back I'm actually impressed just how far back Valve saw this happening. Decoupling PC gaming in its entirety from Microsoft's vendor lock-ins is in the best interest of all of the companies in the gaming industry, but it takes a rich private company like Valve to start doing the hard work for long term benefits instead of always chasing the short term profits.

Even if tomorrow Microsoft launched something that pulled ahead of SteamOS, it would still be in the gamers' best interest to stick with the open platform. With a consistent, large userbase on an open platform it will eventually eclipse anything Microsoft could ever muster.

Linux, currently, cannot handle everything Windows can unfortunately.

I mean it could, companies just don't port their software because there's not enough market share to justify it. And there's not enough market share because the software isn't there. and the software isn't there....

Valve is doing this for strategic reasons and also because they wanted to start the handheld PC market (Steam Deck). Strategic reasons: Microsoft could at any point buy several important gaming studios or distributors, distribute a lot of games (maybe exclusively) via their own store (they even announced that several years ago, but they didn't do it in the end). MS could even implement small things which make Steam perform worse on Windows, as its 100% controlled by MS. If you compete directly with Microsoft on the Windows platform, you will eventually lose because MS can do some very tiny tweaks which happen to make your product be more annoying or slower to use than Microsoft's own. That way they'll still fly under the radar for anti-competitive behavior. So Valve has to ensure that their main business model (selling/distributing games on Steam) remains future-proof, and that means more independent from Microsoft's agenda. To do this, they need to push a fully neutral, but viable alternative to Windows for gaming. Which is Linux.

I'd possibly argue a full GPU could be detrimental. Maybe best to aim for Steam Deck performance in a home console but with the potential for a GPU installation later on. Obviously being a home console would allow for a more power hungry but performamt APU. Maybe they could attain Series S performance whilst being a much more open platform.

SteamOS 2.x was based on debian, but that hasn't been updated in years. The Steam Deck launched with SteamOS 3, which is actually built on top of arch and is much more akin to Manjaro. As for your question, it's mostly the "game mode", which uses IIRC Wayland and wraps games inside gamescope which provides a bit more control in the form of controlling frame rate, resolution, etc externally, but regardless, that can and has been achieved in custom distros. I think the main appeal of SteamOS honestly is the package of an immutable OS optimized for running games on steam. It prevents non-linux users from breaking things and tries to make it feel more like a "console" with a "desktop mode" (KDE Plasma) and "app store" (ala flatpaks). I've toyed with the idea of running it or similar on my gaming PC but always run into the difficulty of Nvidia drivers on Linux.

"Works" to varying degrees. It usually needs to be tailored to the hardware.

They are way more powerful but makes less use of the power. Also way more expensive most of the time. Valve actually sells the Deck at a loss and hope to get it back on games. It's currently the best value for money.

They would then also “just” need to develop and ship an x86 to arm translation layer, like Rosetta 2.

Lol there's a whole lot more to it then that. On top of needing to have proton/wine support ARM as well, which is super complex.