Hi, there are much more players at Arcade around 16:00 - 21:00 (European Time). So if you live in the States that would be 10:00 - 15:00 I think. Okay It's not as crowded as Skywars or Eggwars, but Arcade can be crowded too. You'll find many players playing there everyday. If you are at Arcade around that time I will guarantee you you don't have to wait that long before a game starts.
The best way to update Arcade in general is to make more maps for each game and keeping the old ones too ofcourse and fixing some major bugs (SCB double jump) would be great. Oh and I hope they can fix the laggback at TNT Run. I don't have evidence, but you can find the bug (I think It's a bug I'm not sure) at one of tacosbefriends's stream.
Anyways Arcade isn't dead, but that's my perspective ;)