A mix between true skill and arena rating?

What do people think about the matchmaking ranking system? what should it be?
I personally loved the true skill system of halo 3 as it meant I frequently got competitive matches and felt that I had a good measure of my true ability to play the game, rather than on reach were the only ranking coming , even remotely close to true skill was the arena ranking and whilst they had the right idea of ranking people based on individual performance, the raking system meant you had to play the game a lot to play at a higher level even if you were already good enough and as a full time student with part time work this wasn’t as easy for me, also it took your 3 best meaning you could suck out on 20 matches and get a good ranking based on your 3 best meaning it was a true representation of your skill. A mix of true skill that levels you as an individual based on your individual performance sounds good to me. So if you are consistently good or bad in a ranked playlist your rank can go up or down or sit still if you are consistently performing to that level