Personally, I think it's that^^^ and also because the old, landrace strains that were exclusive to a specific region, often had lower THC levels but they also had a much stronger smell/terpene. It was the strong smelling strains that got selectively bred out of existence by modern methods, because the strong smelling plants were a dead giveaway to where there was an (at the time) illegal grow going on. And they sent people to prison for that kind of thing. Breeding out the strong smelling strains while increasing the THC levels became the goal if you planned on not getting caught. Flavor and smell took a back seat for many generations of plants.
God bless those growers for continuing to grow in spite of the threat of prison back then. It was a sad circumstance that they had to do what they needed, in order to minimize their risk. Hopefully, some of the old landrace strains that had the strong smells will be found and make a comeback. And when they do, I'm pretty confident that people will realize a major difference and see that it was never just a matter of increasing the THC content to make a more potent high.
I tell younger people this all the time....If anyone thinks that "stronger" weed means higher THC levels, then just go out and get a pure THC isolate (like a Wizard Stone, for example) and dab it. You'll see that THC isn't "the" thing. In fact, I'd wager that most probably wouldn't like it. It certainly didn't make me feel "high". It made me feel a bit uncomfortable and it wasn't cozy and warm at all. I wouldn't even associate the feeling with getting high by using pure THC. It's a whole other thing.
