I said many times and I'm tired of saying:
The system is heavily abused and exploited the way it is. Reporting one game won't save the world. Trust, his own team will report him, and if he falls in your team you can report him.
But you don't give the players the option to report their rivals, or else we got more abuse on the report as it is.
One of these days I went PA mid for some fun, found an account buyer on the lane, destroyed him, when the clock reached 22 min I was 25+/0/10+, filled with items and buying Moonshards for my team.
I received 4 reports that game because "PA is broken hero for noobs, I'm reporting you for that."
Envy is a factor to be considered in the report system. Some noobs got mad because I raped them with a PA. They wish they could play that good, so they reported me.
And one even said "I hope you get low priority so you never pick PA again."
Yeah... And I also had a Tilting Magnus on my team this game, he refused to give me Empower, because he was also envy at my performance, so he was stealing last hits from camps, trying to sabotage runes and even stole the aegis of a roshan and denied the cheese.
Reporting Enemy Must Go.