The games aren't dying out, since the sales for X and Y were quite good (Around 9-14 mil iirc). The games, whilst going on a similar route since Gen 3, do shake things up occasionally. For instance, Gen 5 completely changed the common set up for the plot when you were meant to face the Champion in Black/White.
As for this mini-discussion of the anime arcs:
Kanto - Overrated and lacking in logic at many points, especially the "aim for the horn" scene. Still a little better than many of those to succeed it though.
Orange Islands - One big filler, though the challenges of the Orange League members were at least interesting. This should've been where Ash/Satoshi's story arc ended though, much like the Pikachu Denki manga.
Johto - It was alright, but got dragged out during the middle of it by some of the most pointless filler in the series.
Advanced/Battle Frontier - Had better character development than most of the other arcs, yet was one of the least entertaining and drawn out parts of the series. Battle Frontier was pretty bad too.
Diamond/Pearl - Perhaps the most filler heavy part of the series, awful filler at that. Pikachu's nerfing was perhaps the most extreme in the series until Black/White, plus Team Galactic were made even more redundant than Magma/Aqua anime-wise (Cyrus didn't do much at all). Had it not been for the quality improving during the Pokémon League segment, it'd be a good candidate for worst series.
Black/White - Dropped it about 10 episodes in. From what I've heard though, plot points such as Team Rocket's involvement as a whole and Plasma's threat to the protagonists may make it better than DP though.
