What's the point of a report about an early exit from a match?

Having played for some time and reporting hundreads of players the only "We took action based on your report" emails I have received are for toxic chat / VC.
Those I have received about 10-20.

I have encountered few blatant rage hacks and reported but not received the email. So with that information I can draw conclusion that inappropriate behaviour is the only reporting function thats actually working.