I can tell you that lots of houses weren't remediated like you'd expect. An extra layer of paint, and now 50 years on since the 70s both are chipping sort of thing.
Yeah OP is completely wrong. There is tons of lead paint on the walls in just about every city in the US. Remediation has been completely ad hoc and the restrictions on selling a house with lead paint are almost always a single sheet o paper that says “Sign here to acknowledge that there may be lead paint.”