A lot of people, including myself, consider a phone call an extremely unwanted barrier. If you can sign up without speaking to a person then you should be able to cancel without speaking to a person, no matter what.
Phone call anxiety is a real thing. No idea why I have it, but I do
Not at all. You can go to a website and click a button in less than a minute, and you don't have to do it during business hours, sit on hold, or deal with a pushy sales rep trying to convince you not to cancel (well, unless they do what Adobe is getting sued for).
There is no legitimate reason to limit the options for canceling a subscription or adding barriers to the process. It's always an anti-consumer move. If you don't want your customers to cancel, then don't give them a reason to.
That's still 2 minutes and one phone call too much.