Probability this simply turns into a weeks-long debate (of course, ON Twitter) about whether or not the tax structure is too difficult for even large firms to easily comply with?

Fun thing: there are a few, easy to integrate services that will give you all the information you need to remain compliant. You just need to integrate them in your checkout workflow - and then actually report the taxes and pay, which is the much more onerous part.

Which is solved everywhere, except US, by showing the end price to the customer and eating/calculating the taxes "under the hood".

US companies need to comply with an even more complicated tax structure (due to the existence of state and city taxes). The only difference with the EU is they need to show it in the upfront price, rather than only in the final billed price.