Amazon Prime is particularly heinous about using dark patterns to confound users into risking forgetting but ultimately you’ve already paid for the month, year
I can confirm this to also be the case with most streaming giants plus the less-giant Shutter
Edit: comments have pointed out some notable exceptions such as services through Apple and HP Instant Ink
Also not true for HP’s “Instant Ink” subscription service, which I can tell you from experience will brick the perfectly full cartridges already in your printer as soon as you cancel, even if you have not yet reached the next billing date.
Always forget printers exist but can’t say I’m surprised. Added this to the list of exceptions and made the title more accurate