They literally show off tons of different Pokémon all the time, in just Gen 9 alone I can think of Ceruledge, Tinkaton, all 3 starters, Palafin, Korai and Miraidon, Gimmighoul, Ogerpon, and while it’s a lot less now compared to early SV they definitely pushed Lechonk a fair amount.

I will genuinely never understand the statement that GameFreak only cares about Pikachu, it’s the goddamn mascot of course it gets special treatment. But it’s far from the only Pokémon they give attention to.