I know you asked for the opposite, but it actually sounds like you’re a good fit for the Steam Machine. You didn’t mention the price being a deal breaker. You will appreciate the form factor and quietness. You want performance, but you’re apparently not a stickler for it, and the Steam Machine should be enough performance for a long while, especially with the market stagnating. You already like Linux. You mentioned a busy life, and the Steam Machine doesn’t require you to build it, makes getting in and out of games as fast as it’s possible to be on PC, and is popular enough that you will have the most possible reference material for quickly setting unique things up (like emulation) or doing troubleshooting.

Now, it does have less modularity and upgradability than your typical desktop PC, including small form factor builds (usually still at least twice the size and noisier), but how big of a negative that is is up to you.

You mentioned the Steam Deck being too heavy. Have you tried using it, or is that an assumption based on its listed weight? I personally find it so well balanced that it feels lighter than it actually is, and that’s apparently a common opinion, but I’m always interested in seeing other opinions. It’s probably the best backlog killer available now (including over the Steam Machine) if you can work with its compromises.