The fact that it can be done or even relatively easily means nothing. Whether teams are hired in-house or the task is outsourced does not matter, it still costs a decent sum of money and requires ongoing maintenance costs. You need additional devs, you need QA and customer support, you even need new features in your client. You can’t just wing it and bundle some packages, we are not talking hobby projects here.

Again steam did not do this to drive game sales, otherwise they'd have done this before they needed a deck solution. And this is because stand-alone the amount of game sales this would drive is nothing to major vendors because most linux gamers are willing to use heroic/lutris/bottles/wine whatever themselves or dualboot / vm passthrough to play what they want.

And you keep hinging on steams hardware sales figures but it is not like the praise or demand for steam deck comes from it running a linux base. It would be more accurate to say people love it despite that fact.

The praise steam is getting and what is driving steams device sales numbers comes almost in its entirety from the hardware platform being really good and the price being really low. And this comes back full circle - this is almost exclusively why steam invested in linux compatibility.

So no, steams hardware sales numbers don’t speak for themselves.