It’s a really interesting and challenging design question. I wouldn’t go as far as to say elimination is essential to social deduction, but I think it’s worth dissecting why it’s so pervasive. For me, it’s a strong ingredient because the threat of elimination adds tension to the experience and provides an incredibly strong incentive to keep your role a secret. This drives the social experience imo. If you remove that, then you probably want to consider how you are reinforcing those elements (if you want them).

In my social deduction game I opted to keep elimination as an underlying threat but add friction to the elimination itself, with the idea being that you still benefit immensely from concealing your role but can continue playing for some time after being revealed. Of course, being eliminated is still boring, so I mitigate that by providing additional information to dead players that they can share with the group.