Correct. Though note also that lead paint was being phased out already earlier than 1978, so single-family homes built after 1960 or so are less likely to have lead. That still leaves a lot of dwelling units, particularly those that were not renovated recently (i.e. cheaper places).
Unless it was a 20 year old playground, the playground was probably made in SE Asia. We got miniblinds around 1990 that were manufactured in China, but sold in the US that were recalled due to lead paint.
