The things do work however quality of the devices vary. US Customs regularly confiscates shipments without cause. They’re legal so why confiscate them?
The real issue is an alliance between the US government and the tobacco companies. The government hates them because they haven’t figured out how to tax them as heavily as analog smokes. Tobacco companies are against them because it cuts into their bottom line.
Billions of dollars. That is the big shoe to drop. Gubmints will have to admit the truth.