I disagree entirely on shulker shells and elytra spawning too frequently. They're non-renewable and it shouldn't take literally hours of flying in black void to get them. There's no skill in it, it's just a giant boring time-sink.
As for diamonds, you can make a village that gives you all diamond things, the frequency of them in the End really doesn't matter.
If you think it's too easy to get things from the End, then just don't do it and see how much worse your game experience becomes.