There are some that are genuinely dangerous and bad for society, but there are tons of goods that are "the same thing but half the price because it lasts a quarter the time" that have genuine utility.
Harbor Freight has basically made a drop-shipping business out of it. I often have tools that I need but will probably use 4 times in my life, and the Harbor Freight stuff is crap but will probably work 4 times.
Copy that over a bunch of verticals and it starts to make sense. Clothing for a costume I'll wear maybe twice, niche cooking gadgets for very specific things, tools to do a one-time repair on a car, a flash drive to turn over photos to family members, yada yada.
Forehead hit hood, but I caught myself so it was a "gentle" reminder instead of a concussion. I should have splurged that time I broke a socket tightening an axle bolt. 150 ft-lbs + 180 degrees is a fair bit of torque.