The problem is your parks, destroy the majority of them. Looks like there's an issue where when you have lots of parks your commercial demand goes wayyyyyyyyyyy down. Which in return slows your entire city down because its unbalanced. Your industry needs more commercial which lowers the job need which then residents don't go shopping or have places to work. The issue is starting to appear everywhere as more and more people play the game and start getting past this 30-40k mark.
My best areas are actually where I have just enough services and even with traffic jams in the area here and there they strive vs the areas that are covered with everything they seem to do far worse.
My best areas are actually where I have just enough services and even with traffic jams in the area here and there they strive vs the areas that are covered with everything they seem to do far worse.