Gen 8 feels like the most uninspired generation and you only have to look at their main legendary pokémon.
>Zacian and Zamazenta, the pokemon sword and shield.
Aegislash was already the pokemon sword and shield in Gen 6, and it does way better.
>Eternatus, an alien pokemon, which came from outer space inside a meteorite and has a core as its main organ.
Deoxys is literally that.

Basically this generation reuse many existing concepts, also, the origin of Dynamax is very similar to the origin of the Mega Evolution in Hoenn. Basically the impact of a meteorite and its consequences.