Despite what a lot of people may believe, I think Pokemon has gotten massively far.
I can only speak on part of the games, but I don't think people give Game Freak quite enough due credit when it comes to them. It's kind of crazy to think about it if you've ever grew up around the time of the link cable all the way up to now how technology has advanced enough that we can communicate with online friends all the way across the world with ease when that wasn't possible when we were kids.
Graphically is where things may get a bit more debatable since there's always going to be the folk who prefer sprites over models and I think that in itself is fine, but one would have to admit some form of progress even looking at the sprite style year after year starting from RBY and how polished they've become.
Really though, when I look at Pokemon creatively made such as Dhelmise and compare them to any Pokemon that was made from the Kanto days (for comparison's sake), Game Freak has come quite far in terms of Pokemon creation as well. Not all of their ideas are great, but I think they do well more often than not.
It has come pretty far. It has had its ups and downs, but mostly ups. The fact that it's still immensely popular is a testament to its success. I first played Pokemon on the original Gameboy (the thick, gray one). I really credit that experience when I was very young to setting me on my path to being a fan for life and a gamer.