You are 100% correct that a person ought to be entirely independent upon reaching adulthood, if he/she so chooses. You know how you do it? "Mom, Dad, I'm not going to play by your rules any more, thanks but no thanks, I'm going to make my own way out there in the world." How successful are you going to be as an independent person if you don't have the balls to make a simple statement like that, if instead of declaring independence, your only means of resolving this conflict is by calling the cops and sending your parents to jail because they "abused" you by asking you to install some app?
Parenting is not all about money. Some parents have a very specific and tyrannical idea of how their kids 'should' turn out, and will not hesitate to spend money, beatings or literal blackmail to achieve it.
Think of a wealthy father that beats his daughter because her behaviour is 'improper', or forces daughter/son into marriage. Or of Eton College which is stupidly elite and expensive, yet famous for beatings. This stuff is common enough that I've witnessed some of it, and it's not pretty.
I am not claiming the proposal on offer here would be of any help, just trying to clarify the issue
With all due respect, you've gone way, way out on a tangent that has nothing to do with the original statement or my initial reply.
He is tyranically fighting parental tyrany? How ironic.
For every happy hamily I know one that's fucked up. Once you are 18, you are free to escape abusive parents, and that often means you loose their financial support. Sometimes thats what you have to do