>>52165607I could be way off but this is the timeline as I understand it...
Gen 1 blew up in popularity because it was the fade at the time. Gen 2 saw a slight drop off but was still riding the original wave of popularity pretty well. Gen 3 was the first major drop in relevancy. The original fanbase was "outgrowing" Pokémon and the fade had passed. Even with the new mechanics, it still felt like more of the same to the average player. Two other things to take into account is that misty was no longer a main stay in the anime and the designs of gen 3 had a bit of a different style to gens 1 and 2. Gen 4 saw a resurgence because Pokémon was now being introduced to a new generation on top of the old diehard fans. It felt refined. The new designs were less "jarring" than gen 3 but kept still had a unique and cool feel to it. Also, I think the card game sold well at this time as well with all of you younger kids getting into Pokémon. Then gen 5 was another drop in popularity. I think it was a similar situation to gen 3. The fan base outgrew Pokémon and there was a general Pokémon burn out. Also, with the internet becoming even more accessible, memes about how "the new Pokémon designs are bad" could spread. Gen 5 was very ambitious in changing Pokémon, but it just wasn't the right time for that. The novelty of 3d Pokémon and mega evolutions was enough for gen 6 to have better sales, but the burn out was still real. Still a recovery. Gen 7 exploded pretty much completely because of Pokémon go. The anime has a good season prior to this helped build the hype for this gen, and some other stuff, but it really was just Pokémon go saving the franchise. Gen 8 was just riding the coat tails of gen 7. It is feeling like a cash grab didn't help, but with Covid and an increased acceptance of man child behavior, it did well enough. Gen 9 will probably do poorly because of burn out of the franchise and the game being underwhelming.
