I don't think the USDS makes all or even most of the current federal gov websites.
We also helped with design and infrastructure support for ssa.gov (launched earlier this year) with a contractor team to try to boil down 60,000 pages to ~30 pages that people tend to use.
// opinions of a former USDS, no longer with the team
And they're involved with the Department of Education, although I couldn't find out exactly what they built.
They did help change over the old va.gov to the new va.gov (which was built as vets.gov), which imo has been a huge improvement.
(There are still many, many problems with the VA and its website. Just saying that 1. the new va.gov is a big improvement and 2. the USDS is far from being a single point of responsibility for it, or even _the_ major point of responsibility)