know that feel, especially if you come from a game where the focus of balancing and power were on the lower tier, than the highest tier.
Most of the time when a new SSR unit is released, it comes with a R and SR unit, so basicly the amount hardly differes. although raid events introduce a SR for "free" each time.

I believe someone mentioned that there will be a bunch of new R's in the Gem gacha soon, but don't quote me on that. if i am wrong, just correct me.