I built myself a gaming PC about two years ago. I've been an AMD supported for decades, so I went with the best CPU AMD was offering at the time. Two years later, it's still the best CPU AMD offers.
Well, I built a PC 7 years ago. It STILL is within roughly 30% of the top comparable system you can build today. These are Intel CPUs btw. Their performance plateaued with the Sandy Bridge core design, although the Gulftown I have competes well with the top end available with even the current i7s. Yes, the 4790K is faster single threaded, but if you OC both the extra overhead available on the Gulftown closes the gap considerably. And overall performance the Gulftown doesn't get doubled until you go to the current 20 core monster that isn't even available for desktop use yet.
So just realize that Moore's law is done, at least for the last 8 years it has not held. Real performance has barely doubled in the last 7 years by any measure. We have reduced power and heat during that time frame for equivalent performance. So there's still progress, but it's not the 1990s through 2010 heyday we experienced where major performance improvements occurred pretty much every 2 years.