RPGs are just games where you progress your character through levels/experience/stats/equipment. That’s why Elden Ring and Baldur’s Gate are both RPGs, even if they are completely different games.

And I’ll add on to that my opinion that genres are not a rule or an all-encompassing description. The common genres we use for games describe parts of the game, but most games fit into multiple genres. A tag system like in Steam is probably more fitting to categorize games.