They don't even qualify as proper videogames for me. Videogames are things I sit down to play, make an event out of it, bury hours of my life on! Mobile games aren't worth that sort of investment.
Instead, they fill a different niche - time-wasting entertainment for the toilet or commuting. Pokemon Go is a great way to spend 15 minutes at the bus stop or while waiting for your food to arrive at a restaurant, and games like Doodle Jump or Templerun are great ways to kill 3 minutes of dead time.