Crypto is unwieldy by design, but apparently we just need to find magical computer scientists to fix it for us
Let's take a simple use case: buying mullvad vpn.
You can use your credit card, which does tie your identity to mullvad (which doesn't really matter because if they get subpoenaed by the police, the police will give them your account number once they find it and mullvad will be able to find your logs).
In that case the process is pretty straightforward. I click on "pay with credit card", the website redirects me to the payment platform, I enter my card number, I get redirected back to mullvad and they give me a code I use in the app to add one more month. It cost me 5$ exactly which is a nice integer and I didn't have to enter it anywhere anyway. My card was automatically debited for the amount and I receive text confirmation that I indeed paid the amount.
The price is important though, and we'll come back to that later, because no matter the price of the item -- 1.37$, 0.99$, 1067.98$, I can pay it with my card without hassle.
Or... you can buy mullvad by going to a third party se