Few people would, that's not the point. It seems you are not understanding this part: "shift from large-scale to small-scale extraction". The claim is that cocaine would partly shift to "at home" and local production, which GP correctly points out is currently very common with DMT. The comparison is made because DMT currently has a similar legal situation to what GP suggests for cocaine: legal plant material, but the purified/extracted substance is illegal.
> It seems you are not understanding this part: "shift from large-scale to small-scale extraction". The claim is that cocaine would be fabricated "at home" and locally, which GP correctly points out is currently very common with DMT.
Couldn't you say the same thing about meth, especially in the past when pseudoephedrine medicines were easier to get? It sounds simple enough that regular people can make it from a receipe, but the cartels still traffic it: https://www.vice.com/en_us/article/bvgazz/sinaloa-cartel-dru....
I believe cocaine is a bit easier than meth, though I'm no chemist. In any case, you're certainly right that it wouldn't kill the black market, but it would still weaken it (I edited my post on this point, sorry for the confusion).
If you can get an ephedrine compound a synthesis for meth is possible where you just throw everything in a pot and come back to it. Small scale production used to be fairly prolific based on total consumption. That said its total production volume in that manner was low.
