Actually the more people counted in a state, the more Federal funding that state gets for its use.
Also it is to decide how many Electoral votes that state will have, and how many Senators and House of Representatives members ( Congressional seats) it can have for that state.
Of course with more people in the state, the more the Fed money has to be spread around, to give them all services, programs, schools, taxation, etc. So head counting has many good reasons too.
So giving a correct head count is really a good thing for your Gov.'s and Mayors. The statistical data gets analyzed.
I just don't like them getting nosey into other matters that I don't think they should be in.
BTW,
The cost for the last 2000 census in the U.S. was estimated to be $4.5 billion, more than $15 per counted person.
I wonder what this one will cost us?