Greninja's Popularity Still Declinin'?

I have thought that Greninja's popularity is still declining because none of the other Greninja have been set to appear in the Pokémon Sun and Moon anime series, while none of the other Pokémon cards of Greninja have been made for the Pokémon Sun and Moon TCG, while Greninja should've been included as a playable fighter in Pokkén Tournament & DX for the Wii U, Japan-only arcade machine and Nintendo Switch. Do you think so or not?

I sincerely hope so.

But it's fairly common for Pokemon to pop in and out of the series as a focal point - Charizard in particular comes and goes at the writer's whims, as does Lucario. I wonder if the reason Greninja wasn't a fighter in Pokken was because of its inclusion in Super Smash Bros. instead...admittedly that doesn't make a huge amount of sense, but it's a possible reason.

What? Is Greninja's popularity declining? Either way, I still love this Pokemon.

I think Meyneth's point regarding Greninja's absence in the Pokken games is right. It was likely done intentionally due to it appearing in Super Smash Bros. 4 which is usually reserved for the absolute most popular Pokemon characters, like Charizard and Lucario, as well as mainstays Pikachu and Jigglypuff.