Blockchain crypto currencies, like BTC - and most of the others, have been introduced to make the transfer of money much quicker, and more private. EVERY transfer and payment you make via your bank account is recorded. Very often nowadays you even have to obtain permission from the bank to transfer your OWN money - or make a payment. As soon as it hits your account your money becomes controlled by others.

Of course, it is in the bank's interest to make sure you pay your income tax, after all it is the banks who ultimately recieve ALL income tax as the interest payments on the loans they make to governments. Do you think you your bank will allow you to forego paying your full income tax. The best way you can avoid paying income tax is by using your bank as little as possible, and using crypto-currencies instead.

Of course, the bankers, through their 'puppet' governments, control and manipulate the crypto-currency markets as much as they can. However, using most crypto-currencies gives you a higher degree of privacy and control over your own money than using a bank.