There are items that can only be bought with gems - savage scout, island deeds, premium time etc.
We get 100 gems per week if we log in every day.
It will take many years of logging in every day to earn enough gems to buy these things.*
Since the level 75 upgrade, we rarely get star coins. These were useful for buying buff kills (assassin / catapult etc) and for buying gem packages (max 100 gems per week). Of course, without star coins, we can't buy these things now.
Maybe BB could let us buy star coins with stalks? Or maybe even buy buff kills / gem packages etc directly with stalks?
* Yes, I know we could simply buy gems with real money, and I don't mind spending a bit of money, but I think that kinda ruins the game for me, takes away the challenge. I love a challenge, but logging in every day for several years to get the gems is a bit too much .....