Drop the income tax, make it a flat tax on consumption (both products and services).
Ahh, another person who thinks that everyone paying the same amount means everything is fair. Flat taxes are inherently regressive which means that while everyone is paying the same amount of tax for a given purchase, the impact on their lives is not remotely the same because incomes are not uniform.
You pay tax on raw materials and collect tax when you sell.
This is roughly what a value added tax is. There are advantages and disadvantages to this taxation scheme just like any other.
you can make 100m$ and pay no tax until you spend it
Sounds like a great deal for the millionaires of the world. However for those of lesser means they don't have a lot of disposable income to hold on to it kind of is meaningless.
it would make it easier for everyone to understand, it would be easy to track as tax would happen when money changes hands.
I am an accountant. I think you have no comprehension of the administrative burden you are proposing. Currently my company pays zero sales tax because pretty much everything we sell is resold by someone else or incorporated into another product. This means we also don't have to spend money tracking, a bunch of transactional costs and remitting payments to a government. Tacking a consumption tax onto every transaction we make would cost us a small fortune both in administrative overhead (salary) and needless changes to procedures and software. The conversion cost alone is frankly prohibitive.
You think it is easy to track every transaction and I can assure you that you are wrong. While it is achievable it is very much not trivial to administer.