i guess it wont happen especially if you are receiving higher salary then company you are working for well render their full compliance to the government that if you refer to avoidance of income tax. You may face a lawsuit if you will not decalre your salary or else the company you are working for will be reprimanded or put to closed. You cannot escape salary income tax especially if you have fixated income. However, there are certain job that receive unfixated income and will more likely to escape income tax. But in terms to btc if the owner of the company pays you in btc then therefore they are also held liable of the employment agency since they have worker but they could not show the transparency of the salary pay. Usually the employer will issue a payslip. so bitcoin wont kill income tax.

If bitcoin is accepted world wide to buy all the things like US dollar, then only income tax can be avoided.But, it is not the case.Every time, for buying anything, we have to convert bitcoins into fiat and so we have to pay tax for the fiat converted.To my knowledge, we could recharge our mobile and hardly buy products found in some offers online produced by individual persons. It would take a long time for us to avoid income tax on our bitcoin earnings.

i dont think so. the world changes everyday. the new things will come, old things need to be removed. Crypto will become the offcial currency of the wolrd and the Governments have to research and find out the way to collect tax.

No i think there is a possibility in near future. As Bitcoin is a peer to peer transaction there is a possibilities that banking system will be dried up and the government will suffer a loss of revenue due to taxation. But for now there are lot of people who used fiat as legal tender in buying basic needs in our time I think it will not happen, but maybe this is the time that we might think any means that the government can also earn the right taxation revenue, because government also is a very vital in protecting citizen rights.