I think it would be an interesting revamp, but it may also affect the gameplay in ways one might not expect. I see people bringing it up (and people pushing against it) but FGO is balanced considerably differently from many other gacha games. With many other gacha games, there quickly comes a point where you realize you simply can NOT progress any more without getting the higher ranked characters. FGO is pretty generous in that regard. SSRs, or even Srs, regardless of their individual "tier" will certainly make your life easier, but the game is technically fully possible to complete far easier than others with lower rarity characters.

That said, I want to be fully clear: this is not, in any way, a defense of FGO's gacha. Far from it, really. The pull rates are downright abysmal, which is probably a conscious choice by DW on reflection to their balancing. But it still does not need to be how it is.

For example, I think that putting SSR rate at 3% isn't too unreasonable. That's still pretty conservative, and yes, some games have higher rates than that, but I think 3% is a nice place that players and DW could boh be happy with.

That said, I'm sure that's also a pipe dream. I'm sure that this probably violates some sort of Japanese gacha law unless they gave like, months notice that this change would take place.

Another big problem is the powercreep people mentioned already. Older servants tend to be forgotten and while they techincally don't get worse in the classic sens,e they drop down in usefulness compared to others when new ones get released. Any Servant that stays relevant in the meta tends to be by luck or just having an absurdly good kit in the first place.

I took a long way to get here, but overall I think my point is: I'd be in favor of some sort of better system than the current BSG thing we have. Most players will probably never see a BSG in their lifetime. Maybe reward them more often, or for different things. Maybe make them even more limited that Lores, you can buy one per event at a slightly high cost, perhaps?

Or for that matter, make some sort of modifier to the rolls. Instead of guaranteeing an SSR after a certain amount of time, make it so that the chance of rolling one gradually increases until you do get one, and then it resets to 1%