OP wants the rig to last at least 5 years so I think swapping the processor out in a few years is not something he wants to resort to.
With Intel processors also increasing the core count I wouldn't bet against new/existing games starting to use more cores
The i7 still has HT so 8 logical cores, it's not a complete slouch. I'd agree if it were between an i5 and Ryzen though.