I've never really done much PVP, especially FPSs, and I'm pretty terrible but this has been a lot of fun and I could see myself playing it at launch.
Do they take into account skill level when doing matchmaking? Or am I just going to get my ass handed to me over and over? I do get some kills but I probably die more times than I kill someone LOL. That's one of the reasons I've never played these games.
Everything is going into the account of your skill in SBM in Halo. Your accuracy, damage dealt, assists made, wins, losses, deaths, kills, streaks, I think that they tweaked Halo 5 afterwards (around 2018) that even performance of your positioning in the match goes into the account.
So it's not if you just win you get those invisible skill points. You can win with shit play and you will get basically +0 skill points and you will remain at the same player pool. It's most visible in ranked, but of course, it works like that in socials too, just not that strict. The Player pool is going wider, during the matchmaking.
The Halo 5 system was good in the end and I believe they will transfer it in the future, and one of the rarest examples of how Skills should be distributed during and after the match.
That means, even if you're carried over with good teammates, you probably won't advance, or will until your skill matches your rank and that's it, you will be soft blocked until you git gud.
EDIT: There was a heated discussion on the Waypoint forum a couple of years back on why people can not advance further than diamonds while playing with their teammates. A lot of people raged about that, but when you check their stats, you can see why is it.
For example, I was always on the edge of D/O and I could not get a secured position in Onyx only because I was not playing as frequent and could not maintain my playstyle. The system was dropping me to D5-6 all the time because of being inconsistent. I raged but after going through I think a couple of hundreds of pages of discussion, I realised that it means that the system is working.