I have recently discovered the term metroidvania, as I have been playing games such as "Ori and the blind forest" and "Ori and the will of the wisps".

According to Wikipedia it is a term for a genre of games that was recently-ish coined.

Metroidvania[a] is a sub-genre of action-adventure games and/or platformers focused on guided non-linearity and utility-gated exploration and progression. The term is a portmanteau of the names of the video game series Metroid and Castlevania, based on the template from Metroid(1986), Castlevania II (1987), Super Metroid (1994), and Castlevania: Symphony of the Night(1997).

Do you think these games warrant their own genre? In my mind they were simply 2D platformers. But I have been out of the loop.

I have enjoyed the Ori games a lot, and am now looking at others such as Hollow knight to play some more "metroidvanias".