Using GCC's Nested Functions with homomorphic encryption

The pain points in the article I see is: Which doesn't spell out exactly hon "nontrivial" the cost overhead still is. Proper encryption means the ciphertext is indistinguishable from noise. So...in order to be able to hack everyone's phones? Why are LLM users such poor leaders then? To go anywhere serious you have to make it not indistinguishable from noise. So...in order to be able to hack everyone's phones?