On the other hand, is it absolutely necessary to have a Grand of every class and clear all Olga Quests?
I mean what if you are a E rank luck player whose only real SSR is Mash? Because granding silver or bronze shitters puts them only on par with the C-tier SSR's at best.
It's not like they're gonna do something like make the final chapter so that you need to have a Grand for each of the seven regular classes to proceed, bricking a significant portion of the playerbase, and make it some of the toughest, cruelest and most unfair parts of the game with Level 100* or Level EX nodes to further brick players unless they have at least seven Grand Servants.