How Is a Church Tax In Anybody's or Anything's Best Interest?

Seriously, how is it good for the Church?
How is it good for the civil government?
It seems to me that one ends up with Caesar rendering unto God what Caesar thinks God is entitled to, sometimes at odds with what what the godly say are God's just deserts, and forcing God's people to function as Caesar's bookkeepers, at which they are not necessarily any good, and sometimes inaccurately claiming catholics are Catholics....

And it's not just the plutocrats in purples in Germany who are coming under scrutiny, either.

 Scandinavian Catholic leaders rejected fraud charges against its fastest-growing diocese and defended the local bishop as a “sincere and honest shepherd.”
“Bishop Bernt Eidsvig of Oslo has told us how his general vicariate’s premises were raided in connection with inconsistencies over his diocese’s membership registration,” Precious Blood Sister Anna Mirijam Kaschner, secretary-general of the Nordic bishops’ conference, said in a March 5 statement.
“While Bishop Eidsvig has acknowledged failures in registering Catholics, he denies any conscious or intentional fraud. The bishops’ conference recognizes him as a sincere and honest shepherd of his church and regrets the circumstances that led to this confusion.”....
Father Pal Bratbak, the Norwegian church’s spokesman, also defended Bishop Eidsvig and accused other churches of also “playing with numbers” to obtain greater state funding.....
He added that up to 10,000 “new Catholics” had now also been identified, but cautioned that many migrant Catholics had no fixed addresses and could therefore not be registered.
“Even if not all our figures were correct, the Catholic Church is still expanding rapidly here, and its prospects are good,” the Oslo church spokesman said. “We think there are still thousands of Catholics for whom we can’t obtain funding, since they come to Mass without registering themselves.”