in US all the exchanges are regulated and report the user activities to IRS
All
centralized exchanges. If you don't want the government spying on you and your transactions, then use decentralized exchanges such as Bisq or LocalCryptos instead.
If taxes are being spent on war and destruction, people might start to avoid paying it wherever possible
In the US, we already spend more on our military than the next 11 countries combined, while also bankrupting people for getting cancer. Our taxes are already spent in the most moronic of ways, but almost everyone just pays them for fear of retribution. The government already knows they can do pretty much anything they like with your taxes, since they can just arrest you if you stop paying.