if the citizens of a state refuse to tax themselves for roads, or schools, or adequate police, why does funding those activities automatically become the Federal government's problem?

If the problems were LIMITED TO THAT STATE/COUNTY/CITY, then the above claim MIGHT make a vague sort of sense. But, it is "national" issue when things need to be able to almost anywhere quickly and readily, with few problems. With a patchwork of essentially unpassable roadways and more, that threatens the everyone in the nation, not just those who live where "they don't want to pay". Yet, guess what? If THEY get attacked or need help, they want FEDERAL HELP AND BAILOUT NOW !! So the federal govt taxes them as everyone else gets taxed. In other words, insurance spreading the cost of national risks to all citizens. If the people don't like it, nothing stops them from leaving the US and moving to where they do NOT have to pay for those costs. Where would that be? Good question. MAGA stays in the US because they are TOO AFRAID to go anywhere else. Which is why the wealthy do NOT have their own country--with no taxes, etc. Can they afford it? NO !! Why ?? Because the wealth REQUIRE a massive base from which they can take assets and give to themselves. If they do NOT have that base (which would NOT exist in "their own country"), they would have to pay for EVERYTHING out of their own pockets. They would go broke VERY quickly. Thus, the wealthy are the definition of Welfare Queens. Always have been. Always will be.