The reason there is diminishing returns is simply because intel doesn't have to try. Shrinking the process is terrifyingly expensive and difficult, yet they slowly are doing it.
If intel has no competition, they tweak the product enough to give it a 2017 sticker and sell it at the same price. Because why not?
Only more cores will save the performance trend. So if Intel had any competition in the enthusiast segment, the enthusiast i7's in the $350-500 range would have gone from 4C/8T to 6C/12T to 8C/16T in the years since Sandy Bridge.
If intel has no competition, they tweak the product enough to give it a 2017 sticker and sell it at the same price. Because why not?
Only more cores will save the performance trend. So if Intel had any competition in the enthusiast segment, the enthusiast i7's in the $350-500 range would have gone from 4C/8T to 6C/12T to 8C/16T in the years since Sandy Bridge.