There's skill based match making based on results. (Maybe # of kills too. Not sure). So if you're someone who loses your first fire fight, loses your gulag and finishes 115th every time, your lobby will include more players like that. The teams of guys that are all awesome and win 2 or 3 games in a row eventually end up in lobbies with mostly really good players (and hackers who do well).
There's not enough player volume for the lobbies to be ALL players of the same skill, but its pretty strict. Lots of youtubers complain because it makes it harder for them to just play casually and make fun content. If you're a REALLY good player, you can't really experiment with non-meta weapons because everyone you're matched up against is a super sweaty try hard. In squad games, every team is basically 4 dudes with the same Grau setup (or right now, probably the Bruen, which has emerged as the new go-to gun) that can mow you down in half a second from 100 meters away.
I'm probably a slightly above average player (K/D ratio of 1.22, spm of like 194 and about a 3% win ratio on warzone despite not being a camper and playing quite a lot of solos) so it doesn't affect me too much (some players are worse than me....some are better than me). But i definitely feel like the REALLY bad players are iso'd in their own servers. I get some EASY kills but very few "man, that guy was HORRIBLE" kills.
Link explaining how it works
edit: so according to the data from the link, I'd be an above average player in the "highest skilled" lobbies. Doesn't quite seem right but maybe I just overestimate the amount of players with K/D's over 1.5. I am playing on PC (and other studies have shown the Mouse and KB players end up in lobbies with more M&KB players) so maybe that affects it some. Console players get aim assist and I think that makes playing with a controller superior (if you're at least decent with it, which I'm not) at certain ranges and in certain situations.