I know that there are good recruiters out there worth their weight in gold.
And then there are the others. I know especially in larger cities that potential applicants number can be large and no one is going to remember everyone. Which is why especially the larger agencies have this thing called a “database”
Two recruiters at agencies where I have gone into and interviewed with have my details in their database, both contacted me via LinkedIn. My contact information has not changed in the last several years. One the two even made the “initial” contact. You know “hey I just saw your profile” etc. BUT: He set me up for an interview last month. So these guys aren't checking their databases to see if that person is already in there. Not to mention notes related to desired positions.