Use Family Sharing, instead of sharing your account. Steam’s Family Sharing program is actually one of the most generous in the industry. It used to be the case where you’d get booted off of a game if the person who owned it opened a game. But they changed it a while back, to where you essentially have a digital bookshelf of games, and sharing members can choose from any game on the shelf. As long as you’re not trying to play the same game, everything is kosher. Or hell, you can even buy multiple copies of the same game if you want to play together, the same way you can keep multiple copies of a game on a shelf.

Switching accounts on the Steam Deck is easy too, because you simply pick which profile you want to use. Plus it means you’re not sharing save files, because each profile has their own saves; Anyone who has ever lost a cherished save file because of a younger sibling hitting “New Game” will be able to see the value in that. There’s very little reason to avoid setting up Family Sharing.