Today, can an indie developer command much larger royalties than this? I would think/hope so? What kind of a cut do stores like Steam take? ~30%? Does that

Today, can an indie developer command much larger royalties than this? I would think/hope so? What kind of a cut do stores like Steam take? ~30%? Does that leave the other 70% for the indie developer? I suppose the indie is still responsible for marketing and all kinds of other stuff.