I recently was deciding between the Steam Deck and a Switch 2, and at the end I chose the Switch 2 because of the lighter weight. I thought the Steam Deck would be too heavy for my weak hands. After spending some time with the Switch 2, I found it also being too heavy for longer gaming sessions.I bought a grip case to make it more ergonomic to hold, but still it gets tiring in less than an hour.
The Switch Lite has the perfect weight, but too many games have tiny text and UI designed for bigger screens.
Image credit: www.windowscentral.com
My Switch (2) doesn't leave the dock and my Steam Deck has been gathering dust. They're too bulky to fill the void left behind by the GBC/GBA/DS I grew up on.
A while back I bought a Miyoo Mini Plus on sale and ended up putting far more time into it than I ever did with the Deck. The dream would be to see SteamOS in this form factor someday.
My way of playing Steam games on a small device is to stream games from my PC to a phone via Steam Link, and using the razer kishi controller.