Maybe this is less of an issue now we’re in the digital era of console games but one of the biggest aspects for me is that if I buy one of these new machines, my existing library is just there. No starting from scratch or worrying about backwards compatibility. It’s a PC that has everything I need from the get go.
The story was the same with the Deck. Granted it took a little while for many games to be fully supported but the transparency from Valve on the store pages about compatibility was great and is in a far better state now.
I just dock my Deck but it was still worth it for the reason you say. Just Works and lets me play my decades-old Steam collection on my TV with the ease of a console.
When I buy a game (even an old one), I always had to choose between Switch and PC. But now PC has most of the advantages of the Switch, and I trust my Steam library will persist and be easily playable more than Switch (although Switch 2 compat was great! to be fair)
The story was the same with the Deck. Granted it took a little while for many games to be fully supported but the transparency from Valve on the store pages about compatibility was great and is in a far better state now.