Different plants attract different symbiotic microbes through their unique carbs, minerals, etc. Said microbes produce their own unique brand of secondary metabolite cocktails: the microbe demographic and what it's fed are a direct impact on unique isoprenoid profiles. (Yes, the microbes use micronutrients and plant waste,not just sugars)
Everyone grows their full library the same and you can tell. People used to grow one tailored "strain" (crop) and it was better. Known by its grower and locale only, not some barely relevant strain name or "indica or Sativa bro" designation. All plants who were lacking or had an abundance in a specific exudate simply shared with its siblings in a common soil. The soil and pheno adapted to each other, no mixed signals from 40 different mutts.
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The whole argument of "old weed sucked, it's tolerance and rose colored memories making stubborn old timers miss it" is absolute nonsense.. A lot of people forget that weed exists outside of dispensary scenes lol. Old timers still grow the same shit they been growing for decades and some of it gets you way higher than any modern stuff. When's the last time you smoked some scraggly seedy brown from an old timer? Some of that stuff will get you a high you didn't even know about. Ever hallucinated off weed? Then you really can't speak on it. Quit pretending the opportunity to try old school weed is gone. Dudes in their 70s still growing it all over the country. Wonder why they stuck with their old Thai instead of something quicker and higher yielding? Hmmmm... Cuz they found the good high and stuck with it. People who don't give a fuck about making money off it.