Pokemon is for people with nostalgia of Pokemon as kids. Anyone who didn't play it as a kid won't like it now.
While im a big fan of Pokemon...tbqh I can't counter what you just said
I'm 23 and I still love Pokemon...and I even decided to watch the whole anime in one big marathon that lasted 1 year(it was terrible and I was forcing myself to do so,though)
But yeah...I can't say that if you never played Pokemon and you are 20+ you will enjoy this...
(no 20+ would enjoy the anime as well...not even Kanto)