So for investments in the US I know there is a double taxation treaty. For both degiro (EU based) and fidelity (US based), I had to follow the W-8 process which basically boils to "I am a citizen of eligible country X, here is my government ID number, I've ticked this box which asserts this to be a factual claim and understand that it's legally fraud if not true, and I can provide documentation to this effect if the US government comes asking". Then the platforms withold payments to the value of my own country's tax requirements and eventually provide it to my country. I think there might be a provision to pay any surplus US tax if my own country's tax liability is lower than what the US would have charged, but it's much higher so that doesn't come into effect.

If I purchase a good or service from the US, the only taxes I'm liable to pay are VAT (sales tax in American terms) and if it's above a certain value, customs charges. These are billed to me, they're not taken out of the American company's share. Companies used to dealing with the EU will show the marked up price and handle the details, most will at least use a delivery company that understands the process and then I pay via the delivery company and then only for the most clueless who've done neither will I get a postman showing up expecting payment before handing it over (or I guess if the value was high enough, a letter from customs asking for payment before they release my goods.

None of this process subjects the American company selling me goods or services to e.g. Irish corporation tax, so I don't understand why if the process was reversed and an individual was providing them a good or service (like Google surely views creators as, I highly doubt they want them considered employees), so I don't understand why reversing the flow should subject YouTubers to US income tax. It feels to me the worst case scenario should be something like the W-8 process where the international creator files some paperwork to say they're not in the United States.