Yeah no problem. I just tried opening arc raiders under my wife's steam account (which she's never played) and it opened as if no one has ever played the game. It brought me to the "create embark id' page.
Edit: now that I'm thinking about it, I also played 'the last campfire' which other family members had played and it started me off fresh
Edit 2: I really think the only time saves will be an issue is if it's a non steam game. Like if you set up emudeck, I'm not sure how those saves work. Or any other non steam game you import to your library.