What does Donald Trump have to say on this subject? He lets us know here:
"I don't think it's him", "I have to tell you he's a different guy", "It's not him"
Read the sentence after that on the site you linked to: “However, it’s not uncommon for public figures to keep their cosmetic enhancements private.” It’s not something anybody is going to be able to prove or disprove, and a commercial site selling cosmetic surgery may mention Biden to attract clicks, but they aren’t going to alienate half their potential clients by coming down on one side or another.
Biden had one of the very early hair transplants. It’s more likely that he had a face lift than that he cloned himself or found a double somewhere.