Is "huge" even adequate to describe the amount of time wastage here? We are talking many seconds people!
Instead of Wotc designers forgetting things, I think it's a lot of people conveniently forgetting the myriad of ways high level players can help their saves: Bardic Inspiration, Inspiration, Indomitable, Paladins, Portent, Lucky, Bless, magic items, etc. Let alone things that grant proficiency like Resilient or Transmuter's stone.
So, for high level characters it doesn't come down to; "There is no way I could make this save". It's more; "I spent my resources (character building and in-game) on other things. And the party isn't prioritizing helping me make this save, probably rightly so because it isn't actually that important."