Just one source. Yes smoking snobs will not use synthetic (but may get exposed still more than they would think). But there are a lot of other types of consumers.
Indeed there are a lot of other synthetic cannabinoids now, JWH018 is rare now.
https://en.m.wikipedia.org/wiki/MDMB-4en-PINACA the most common one apparently has been implicated in deaths but there is not any evidence it causes these problems. Deaths were implicated but it doesn't prove it causes it. Since it's on the DEA watchlist I doubt there are enough MDMB-4en-PINACA addicts to seek it out. It's a crappy alternative to the real drug. It's also such a small amount of people.
Snobs don't smoke "bad weed" but if the supply is gone it will be gone. Banning synthetics will easily kill this market, it is a 3rd rate experience that won't be seeked.
They've already tried banning synthetics. I remember 14 years ago when buying JWH-018 it was sold as "bonsai fertilizer" and then my state banned it by name along with "all other analogues" though I don't know how effective that particular ban was as the people importing/making spice just used different chemicals that weren't explicitly named.
The main draw to this isn't that it's a 3rd rate experience, it's a high that won't show up on drug screens so it was very popular among people on probation back then. Delta 8 still shows up on drug screens but many of the synthetics don't, so if you "can't get caught" but still want to get high people are more likely to reach for research chemicals for the same reason people do krokodil even knowing they will likely have side effects.
Snobs don't smoke "bad weed" but if the supply is gone it will be gone. Banning synthetics will easily kill this market, it is a 3rd rate experience that won't be seeked.