How are people still playing Poke'mon?

I mean really? This game came out when I was in 8th grade and I am 25 now. I don't even know what the current version probably Diamond or Platinum. How many Poke'mon are there even out there, its always the same game over and over. It doesn't even use a complex and interesting combat system. Simply to poke'mons stand opposite of each other and the move slightly toward each other. Great back in 98' when we had N64 at best but really has the poke' producers even come up with anything original in the last 10 years. Now don't get me wrong the original games were great and everyone played them. Like a supped up version of Gigapets. I just don't get it, what ages are playing these new poke games and are they even still any good. I bought multiple version growing up from Red and Blue, Gold and Silver. I am truly amazed at the success of this franchise, when I was in Jr. High and first saw Poke'mon I wondered how long it would last now I am an adult and hear about kids still playing the game. Wow! I must say Wow!