I'm okay with an optional questionnaire, and I often fill them out when I cancel a service. But if it wants me to call to cancel, and especially if it deliberately makes the call longer and unbearable, I have all the reasons to be angry about it. I don't care if it's a struggling startup. A startup is an organization, not an actual life; I'm not going to pity it.

Obviously, an optional questionnaire is not as effective as forcing a call onto the customer. But it's the right thing to do.

True. I'm questioning where is the trade-off and balance between making it more difficult to cancel vs. trying to fix what's wrong.

If I need to do anything more than sending the message (on my own schedule - this part is important, I manage my personal life on nights and weekends) saying “hi, I’d like to cancel please” in order to actually have service cancelled and billing stopped, I’m likely to be frustrated and not give any feedback.

I’ve had very positive experiences with reps replying to confirm my service was cancelled, and then initiating a quick conversation about why I asked for that. I’m usually happy to offer at least some quick feedback, because I didn’t feel like I was being held hostage.

I’d still prefer virtually any other no-contact mechanism for ending an agreement for consumer services, though. Offer me winbacks if you want, add an optional exit interview to the process. But really, please don’t gate my ability to end an agreement I’m theoretically able to cancel at any time behind a manual process that’s any more difficult than my signup was. The intent is different but the end result is the same for the customer.

It's important to be reasonable about this, though. Email isn't secure, and anyone could send an email pretending to be you. If there are irreversible consequences to cancelling, such as deleting personal data held on the service, not only would it be irresponsible to accept an unverified email message as a cancellation request, it could actually be illegal in various places (under the GDPR, for example).

Not providing a straightforward cancellation option via a website where the customer's identity has already been confirmed using their normal credentials is a different matter entirely.

If a customer emails to cancel, just email back a cancellation link that requires signing in. I think that's a good middle ground.

Obviously if someone does email asking to cancel, a suitable method of cancellation should be explained to them.