I'd give up (okay, I've never used) these 'free' features for more storage at the same price. And yes, let's have some more storage levels.
As the devices' OSs (and demands of 3rd Party apps) seeks to use up more of iCloud, the requirement of having to pay just to cover that is almost a given.
Perhaps the basic iCloud account should come with the same amount of storage as the device you buy? If multiple devices, whichever device you set up your account with sets the limit all must share. Still have payment levels for above that basic floor.