taxes can be voluntary like road tax, you do not have to have a car
That doesn't work as a simile: the direct comparison would be, "the price of the car is a tax, you don't have pay it if you don't buy the car."
VAT is only payable on something if you buy it, if you don't buy you don't pay; a bit like a lottery ticket
If you don't buy a VATable product or service, then you are not subject to the tax - that is not the same as it not being mandatory. If you do purchase it, the tax is mandatory. Shit example anyway, who isn't going to buy clothes, or fuel for heating?
So once again, a lottery ticket is not a tax; the tax portion of a lottery ticket is a tax.
Not all "taxes" are levied by a central or local government.
"A tax (from the Latin taxo; "I estimate") is a financial charge or other levy imposed upon a taxpayer (an individual or legal entity) by a state or the functional equivalent of a state such that failure to pay is punishable by law."
If it were up to me, it would be mandatory to study English in schools.