I think some of it is simply a lag in market adjustment: older managers/corporate culture tend to have pre-internet habits about hiring like the assumption that recruiters are necessary to find good candidates and frequently the system is structured in a way which complicates getting people without going through a recruiter.
The root problem is that many places don't measure performance and so you get the same problems which are endemic in marketing where successes are credited to people but failures are seen as systemic. At the last few places, our recruiters literally failed to provide a single qualified candidate (or even strong resume) but this was usually excused as a tough market - and while good people are always in short supply, taking the 30% cut which normally goes to the recruiter and giving it to the person would certainly help.
The root problem is that many places don't measure performance and so you get the same problems which are endemic in marketing where successes are credited to people but failures are seen as systemic. At the last few places, our recruiters literally failed to provide a single qualified candidate (or even strong resume) but this was usually excused as a tough market - and while good people are always in short supply, taking the 30% cut which normally goes to the recruiter and giving it to the person would certainly help.