It also gets you a visit from the feds. Those sorts of purchases are tracked very closely since Mcveigh.
I bought acetone, hydrogen peroxide (in the form of a wood bleaching kit), and hydrochloric acid together in 2002 at a Home Depot and never got the slightest bit of attention.
I also bought an 80 pound sack of ammonium nitrate from a fertilizer dealer in 2002 with cash. I didn't show ID. The employees didn't grill me at all. I was pretty surprised, actually. I thought there would be some sort of tracking in place six years after the OKC bombing and 1 year after the 9/11 attacks. Maybe they only start tracking when you try to buy it by the tonne. Maybe my appearance (clean shaven white guy with glasses, no tattoos) gave me a pass where other sorts of buyers might need to show ID or explain why they're buying.
https://www.businessinsider.com/oklahoma-city-bombing-ammoni...
" the new legislation will require anyone buying more than 25 pounds to register, be screened against a known terrorist list, and require any thefts to be reported within 24 hours. "
Ditto for bulk sugar.
given that fireworks and powder are easily available (re: Tsarnaevs) or relative availability of ANFO (re: McVeigh) and similar stuff or that just one visit to Home Depot allows you to buy components making for a pretty good explosive, i think the explosives are regulated mostly to avoid them lying freely around under the kitchen sinks and in the garages and to avoid being handled by clueless people, not to protect from terrorists.