It would be really easy to simply 'skill match' players by the amount of time they've spent actively playing a live match of the game.

But that would do 2 things:

Make Pay2Win players exceedingly obvious

Make people who've been playing a long time but do infact just suck... it would make them very mad.

Oh! A third thing!

It would make it too obvious which games actually reward and encourage things like teamwork and coordination via well designed gameplay, and which do not.

Don't yell 'but smurfs!' ... come on, every big online game has you log in first, you think they can't grab your MAC address and hardware ids with their anti-cheat?