The game just came out, of course there will be some problems. It has been the same way for years.
Remember BO1 and BO2 at the beginning, it was way worse than it is now.
From what I see, most problems are server-side or bugs in the game (getting kicked out of a party, etc.), so let some time to Treyarch to fix things and everything will run smoothly.
We already have a huge advantage with Netduma, with congestion control and geo filter, and I personnaly don't have so many bad games right now.
Anyway, great job team, I'm sure this year will be awesome