Need? No, but it does make recruitment easier as people take LinkedIn profiles as a source of truth when it is so easy to lie about where you have worked.
Thats a fair point, I do wonder though how long it would take for company to realize though, cause afaik you can make shit up on linkedin as well. Not sure if the companies get notified about that and if they can revoke such a claim.
Depending on the industry/role, companies do background checks or might ask for references from previous employers, so it’s fine unless you get caught