When I bought my 4 core q6600 (I know it's two dual cores stuck together), back in early 2007, people were predicting on TS2 all manner of necessary advancements we will have to get by 2020. We only need 2 extra cores in 14 years. I have friends rocking 920 and 2500K still. Those ancient CPU's are still good especially for CS, TF2, Overwatch etc. My mother is still rocking my old q6600 with an AMD 6770 and can browse and moderate game perfectly fine.
My opinion is CPU's have reached a plateau and there isn't much further to go. When I bought my AMD Athlon back in 2000 it was out of date at the end of 2001. People are gaming on 13 year old chips today, unheard of back in the day. I guess we'll have to wait for Quantum computers to become commercially available.