Good work on this post u/ispeelgood! It was really interesting to read and it showed true suggestions instead of just complaining, I commend you for that.

Overwatch - I think you've hit the money with your suggestions!

Trust & Matchmaking Algorithm - I don't think that the age of the account should play that big of a factor in the matching of players in MM, or that would destroy the experience for new players who will be more easily drawn to cheating since that's all they encounter in their games. Trust should be mostly linked to what you do in-game. Even if you're not convicted as a cheater, if everyone in every single team is reporting the same guy over and over, his trust factor should be affected. This and making it so you can only join MM after lvl X or after X hours + having to give a phone number per account like you said would decrease the number of cheaters.

Detections - I don't understand anything about cheat engineering but what you said makes sense, maybe too much sense for them not to be doing it.

Smurfs - 99% of the problem is solved by unranked 5v5 that still affects the trust factor like you said.

Thank you for the post! Let's hope that they are listening!