I guess a lot of problems come from the stupidly brain dead way people usually write tests (because it's the "recommended TDD way")

Things like using the same setup function for every test and setting up/tearing down for every test regardless of dependencies

Also tests like

    def test1():
      do_a() 
      check_condition_X()

then

    def test2():
      do_a() 
      check_condition_Y()

Or

    def test1():
      do_a() 
      check_condition_X()

    def test2():
      do_a()
      do_b()
      check_condition_Y()

When it could have been consolidated into 1 test

Then people wonder why it takes so much time?

Also helpful is if you can shutdown database setup for tests that don't need it