To be honest I’m not sure how to browse if you haven’t installed the game. If you want to copy from another game you can save the configuration as a template and then import it to the other game.
I have a Steam Deck and was considering “upgrading” to something that has more power.
But then I wanted to play Torchlight 2, an action-rpg designed for mouse and keyboard that does not have controller support. I wasn’t even going to try it, but saw that Runic Games had an input profile for it. The left stick controls your character like it supporter controllers, but it’s all using the mouse. The touchpads work for precise targeting. And I’m able to use all 10 skill buttons using modifier keys and adding the back buttons. Plus I was able to easily adapt this to Diablo 3, a non-steam game without controller support.
If you want to be limited to games designed with controllers in mind, go for one of the alternatives. But if you want to be able to play mouse and keyboard games, there’s nothing that competes with the Steam Deck.
I’m kind of an anti-purist. Give me an emulator with save states and rewind, a scalefx filter and whatever other nonsense. Add on the convenience of emulators and it’s no contest for me.