I've been thinking recently about "historical amnesia" or "generational amnesia." It can also be framed as a "success paradox," where the very success of certain policies or controls causes people to forget the original problem they were designed to address.

Vaccinations, the Voting Rights Act, fighting a war to stop fascism.

It's like after about 3 generations or so, folks forget how bad $THING was, and are just itching to stop paying for the controls that worked, and continue to work.