In regard to co-op, I agree.
I would love to see the ability to have private matches but at the very least the option to rent a server through a service like Nitrado (as I do for DayZ on the PS4/5).
The fact is, we can't always get enough friends online at one time to create a solid team. You are at the mercy of randoms many of which refuse to communicate and run around doing their own thing. .....not playing as a team.
Once in a while you'll find a group of great folks who do coordinate as a team, etc. and you'll have a great few matches. .....but this (so far) looks to be the exception.
I would like to be able to join with just friends up to 8 players in co-op but with less if I want to. This would be a HUGE game changer IMO. If not I'm afraid this game will have a limited shelf life for us as I just don't have the patience for some of these folks that purposely or unintentionally annoy others with their actions, comms, etc.
btw, joined one of our first co-op sessions and straight away this guy says "I F'd your mom". .....then goes on to tell everyone we're all retarded". The insults were then directed at me when I voted to kick but luckily the group agreed to boot. I'm too old for this crap and would rather just play with friends.
This is an awesome game but this is one big flaw that really disappointed us. Please let us rent a server at least if you won't give us a private session option. I don't even care if the difficulty doesn't scale with a smaller team. We would welcome the challenge of facing the same with less than 8 players those times when we can't all get on.