Depends. You can go full privacy mode and make a new npub for each app etc but it's hard to do 'social media' with multiple npubs, it will confuse others I guess. Think about your account management tho, if they can steal one can't they steal all?

I do recommend to make test npub (or a couple) to check out apps. Most of the times you can also login with the npub only so you are not giving away your nsec.

Also check out the extensions which login for you, so you don't have to copy/paste and accidentally drop your nsec somewhere.