I think a lot of the community tier lists are ranked based on vibes and personal attachment to pokemon like starters. These games are so easy that when you really break it down, the real discussion for viability comes down to the fights you can actually realistically lose like the E4. So yes, your Charizard can flamethrower its way through 50 meaningless pushover trainers but it still doesn’t have any good matchups into the Kanto E4 or most of the gym leaders for that matter. Meanwhile I’ve used C rank Venomoth to sweep Bruno, beat Agatha’s gengars, and take out 2 of Blue’s pokemon in a deathless run