THCA isn't special to altinoids like D8 or HHC, there's a similar amount of THCA in dispensary weed as there is in altinoids. It's probably harsher cause they put extra THCA (either by spraying or cold tossing) onto CBD buds to be sure that the altinoid has lower than 0.3% D9-THC instead of just growing THCA buds
Reputable source or not, altinoids are synthetic cannabinoids and they have only been around for a few years. We don't know the real effects on the body like we do with weed. These are harsher chemicals and in many cases so far have been shown to harm the body. The only THC alternative that is safe is delta-8 bc it's not synthetic and it's cultivated synthetically. Also, last year, fentanyl got into the altonoid supply chain all across the country and it still hasn't been taken care of.
THCA is the precursor to THC. It's the raw acidic (hence the A for acid) form of THC. It was discovered back in the mid-20th century but wasn't researched at all until the 90s. No one began smoking the raw acid until the early 2000s. It takes longer than that to see the long-term effects of something. THCA is also known to cause more breathing and other lung issues, filling your lungs with more tar than normal THC.
When its smoked in plant form like that, you're not smoking THCA, you're just smoking weed. When its synthesized, they use other chemicals to extract the THCA from hemp (which is the only legal way to do it). These other chemicals are harmful to the body and residual traces of these chemicals remain in the THCA after the process is over. Its the difference between raw sugar and processed sugar, its still sugar but the unproccesed raw stuff is healthier.