>>254125Yep.
The actual performance of the very-top-end processors hasn't got appreciably better: the only real improvements there have been in performance-per-watt.
So while the mobile processors and the cheap and mid-range desktop processors (celerons, pentiums, i3s, etc.) have got significantly better over the years, the i7s and i7ks have remained pretty-much the same in performance terms.
Just by giving it the best processor available at the time, your old PC can get 95% of the performance you'd get from the 6700K and the parts you'd have to replace just to fit it.