Earlier quoted context omitted.
Revenue tax? We had that before the fall of the wall - not again please. The VAT system works well and should be used more.
Purchase tax would work like reverse VAT. Companies could be awarded tax credits for their sales (not 100% though) and pay tax on their purchases. This would be harder to evade and additionally incentivise companies to do more with less which might be good for environmental transition.
...or you can just use a VAT, which are also paid at purchase. Tech companies have high margins and low expenses, so if the point is to tax tech companies, taxing purchases and giving a credit to sales is literally the exact opposite of what you want to do.