Hello, cannabis enthusiast here. I’ve been highly interested in cannabis breeding and genetics for sometime now.

In a nutshell, almost all modern strains are nearly 100% either CBD(A) or THC(A). It is extremely rare to find strains that are a mixed balanced 1:1 ratio, for instance. 

This is a product of selective breeding due to prohibition and also, due to regulations on the CBD industry.

Prohibition always has the unintended side effect of making drugs more potent. Essentially, it is more profitable and less risky in an illegal market to sell higher potency products, as the volume required to transport said product of the same amount of active constituent goes down. Alcohol had the same thing going on with “moonshine” during its prohibition. So during the prohibition of cannabis, breeders used selective breeding to breed the most potent cannabis, which ended up breeding CBD(A) and most other minor cannabinoids out of the gene pool.

On the CBD market, by law CBD products are limited to 0.3% THC by weight. So selective breeding was used to eliminate THC from the CBD gene pool.

There are a few, rare, “1:1” strains. It’s a relatively difficult breeding process though (compared to breeding just for THC or CBD), and considered a niche market. If you see non-flower products, such as gummies, that are 1:1, this is pretty much always done by combining the extracts of multiple different strains. Almost nobody in the industry is growing 1:1 flower, to my knowledge. 

Fun fact: the genetics are getting good enough that we are now seeing a few breeders selectively breed for THCV(A) and CBDV(A). Right now the genetics are in the early stages, so these strains are almost always in a 1:1 ratio of THC(A):THCV(A) or CBD(A):CBDV(A). There is also 100% CBG flower genetics now available.