Buying a Mullvad scratch card is probably the most practical anonymous method. Usually the fact that you are using Mullvad at all isn't a secret (your ISPs can see you connecting), so outside of a very overcomplicated scenario where Amazon/$yourlocaltechstore are colluding with Mullvad to track individual scratch cards, it's fine.
Mailing cash in an anonymous envelope has a certain charm, but OTOH I have consistently had terrible experiences with the Swedish postal service and that seems to be a widespread opinion.
It all comes down to trust in the end, but over time I've come to trust Mullvad more and more. One particular example that sticks out to me is that they ended subscription based billing, specifically because it required them to hold customer information that they didn't want to have.
- They have strong commitment to open source and have put their finances into that in addition to releasing code.
- They are doing a lot in terms of transparent infrastructure: https://mullvad.net/en/blog/2022/1/12/diskless-infrastructur...
> Also why would I trust them over Google?
For Google your data is the product, for Mullvad you pay for a service.