Before the common availability of HID lighting, very few people in the world had access to high potency cannabis. You got whatever was shipped into your region, and it was almost always seedy. Outdoor sinsimilla grows were rare. Genetics were haphazard. And there was no legal seed distribution.

But those with the best strains in the best regions could grow the best cannabis, and a single hit would make you fall over. I am talking 30 years ago.

Today anyone can setup a grow room with a couple of MH/HPS lights, order a packet of seeds, and grow exactly the same level of quality of the best of the best from back then.

Sure, selective breeding has made it possible to get a bit stronger, but with diminishing returns. It is a few percentage points, not doubling again and again. That's just silly.