For the inevitable minisforum machines comparisons - it's not as bad for Valve as it seems. You can't just add a dedicated GPU to a cheap miniPC with an integrated graphics- power delivery and airflow will have to be different, and you may be surprised to find out that even the cheapest mini PCs with dedicated graphics aren't significantly cheaper than a Steam machine (if at all).

And then my personal experience with these cheap no-brand mini-computers is that their Linux compatibility is spotty, BIOS updates are non-existend, quality control is severely lacking, and you have basically no support. They are also often pretty loud, overheat and die within a year or two. If something doesn't work properly, you are on your own- the manufacturer will have forgotten about this model in a couple of months, and user base is so low that it's unlikely someone will find a workaround.

So comparatively, a Steam Machine would be much preferable to me, considering that it will likely work out of the box with no compatibility issues, will have a typical valve support (which, judging by Steam Deck, is quite fair), is well-built and near silent.

The problem is once the price crosses a thousand, I'd rather add, say, 500 eur, and get a much more powerful machine. I see a point for the cheapest bottom of the barrel gaming pc/handheld (which would be 700-750) with many performance tradeoffs, but this doesn't look like a good enough upgrade from that. A 12+ GB RTX4070-class videocard, 24-32GB of RAM and maybe even an 8-core CPU for $1500+ would likely be more usable in the current market