>>49836602just wanted to autistically note that USUM is a notable exception to this, but the Smoochum/Delibird in question are still both pretty weak and more importantly a little hard to find (both tucked away in a cave you need to spend very little time in).
Game Freak very much seems convinced Ice is strong, not sure why. It was extremely busted in gen 1 due to Blizzard and Freeze mechanics, but that was quickly remedied so it may not explain how this trend has lasted so long. It may also tie into Dragons being a late game type and Ice being the dragon slayers, but again, Fairy. My final potential explanation is that Ice areas tend to be quite late, which seems like the best reasoning- at the same time GF is the one deciding to put the Ice areas late while also knowing that most/all the Ice types will be there, so... I'm sorry if this wasn't too helpful, anon.