The original sin was Wickard, which found a farmer “growing wheat to feed animals on his own farm” was subject to interstate commerce “reduced the amount of wheat he would buy for animal feed on the open market, which is traded nationally, is thus interstate, and is therefore within the scope of the Commerce Clause” [1]. The court even noted that the farmer’s “relatively small amount of production of more wheat than he was allotted would not affect interstate commerce itself,” ruling that “the cumulative actions of thousands of other farmers” acting as he did would.

[1] https://en.m.wikipedia.org/wiki/Wickard_v._Filburn

I think the meaning of the commerce clause is pretty explicit in the constitution. The existence of unreasonable interpretations of the commerce clause doesn't change that the commerce clause on it's own, just with a simple reading of it, isn't powerful. Also worth noting that at least one textualist, Justice Thomas, dissented in that case, exactly because of textualism.