Or ‘do worse than’.

I think I like this one as well. Basically, as you’ll see later on, the expression is (probably) best translated as ‘to be inferior’. Combined with the negation that’s brought with “don’t”, we could rephrase the sentence as ‘Honestly, in terms of ease to play, SteamOS (or clones like Bazzite) aren’t inferior to Windows.’.

‘steamos doesnt under-do windows in terms of gaming’

Another one that I like 😜. But, the double ‘do’ is indeed a bit awkward.

Mind if i ask what language the expression ‘do under’ is from?

Sure! It’s an expression found in Dutch. Heck, to be more precise, it’s a verb that can be split: ‘onderdoen’, but also ‘doen onder’. The literal translation would be, as you’d expect ‘underdo’ or ‘do under’. Here’s the (English) wiktionary entry.

Also agree with everything you said about OSes. I had tried linux in the past but mostly stuck to windows for gaming, then i got a steam deck and ill never install windows ever again.

Valve has truly outdone itself. While I only started using Linux after Proton’s release, the horror stories from the pre-Proton era still send shivers down my spine.