VAT and a vast majority of the laws surrounding commerce at least are simple and have been abstracted away by various platforms ages ago. I invite you to read up on the subject and revise your stance (your premise may or may not be true, I will not claim to know either way) based on something that is actually true.
VAT is very far from simple across the EU and there have been recent changes for online shopping (depending on the amount/turnover per year if might be necessary to charge VAT based on the buyer residence instead of company registration)
Another instance in most EU countries tips (in restaurants/bars) should be subject of VAT, not in the UK for instance.
Different exceptions for deductibles like water for employees (but not coffee and so on)
I think it all depends on how far you want to stretch the definition of "simple". I run a sole proprietorship and don't have to worry about national VAT until I cross a certain threshold. However, if I do business with customers in another EU state, I immediately need to account for VAT and report it.
Add to that mistranslated directives (!), misinformed and uncooperative tax officials and you quickly realize that both "ease of doing business" and the single market are all a bunch of baloney. If I ever launch a B2C service, you can bet your ass I won't be aiming it at the EU market. I'll leave that for when I can afford an expert to handle all the bureaucratic nonsense that doing business in the EU involves.
