it’s not that most governing magically happens at the local/state level, but that the US govt is explicitly designed such that the state is the canonical governing unit, delegating responsibility to both cities/counties and deferring very limited powers to the federal level.

we’re not designed to have many national programs to address domestic issues. it’s up to the states to address domestic issues, with the added benefit that the country can iterate faster to solutions through states working on them in parallel and piggybacking on each others’ successes.