Oh wow they have so many opportunities that they need to go on websites and click buttons to apply? The ones with all these opportunities coming out of their ears are getting recruited, not spamming websites.
Setting up a spam magnet just attracts spam, not the “candidates with the most opportunities.”
Some companies are doing interesting things but unless a good worker already has some kind of connection through their network they're still going to make a direct approach to start the process. Particularly for smaller companies this is very common. That doesn't mean a good and genuinely interested applicant won't have several other possibilities they're interested in exploring as well though.
Setting up a spam magnet just attracts spam, not the “candidates with the most opportunities.”