[2021] After switching from Switch to PS4: "This EA-account is allready in a club"

Unfortunately as of right now, the only way is by leaving the club via the Switch account. Much as we'd like to just remove you from the club in a situation like this, we don't have any tools to do so.

I know it's awkward, but if borrowing a friend's Switch is viable you could log in as a guest on your account there and then leave the club.