Recently, and especially with this gen, the line between i5 and i7 is coming down to the amount of cores itself not the single core peformance. Basically 14 Cores, 20 Threads @3.5GHz vs 16 Cores, 24 Threads @3.4GHz.

What used to be the i7 was (like with the i7-7700) now occupied by the i9 line

The value price of the 12600k is just much better