Imagine a newer pokemon with gen 1 mechanics for a second, For example everything works like gen 1 meaning no dark/steel/fairy, Crits determined by speed, Physical/Special are determined by type etc. Glaceon in this type of environment becomes a ridiculous wallbreaker with 130 special barely any relevant weaknesses with actually good bulk 95 def and 130 special along with maxed out stats meaning it is unreasonable to assume any pokemon is going to take it out in a single hit. Meanwhile it hits you with stab blizzard coming off of a 130 special which very few pokemon can genuinely take.