Yeah PayPal is pretty good here. There's a page that lists all your billing subscriptions and you can cancel them right there.
It's a shame credit cards don't offer the same thing (Chase is able to list them all but provides no contact information or ability to revoke authorization)
The two banks I use provide information about your subscriptions and allow you to cancel any of them with a click of a button. I'm not in the US though (relatively poor "global South"); sometimes it pays to get technology with a significant delay.
One of them can also create zero-cost virtual Visa Golds in a couple of minutes. If I need to use a really sketchy service, I simply create a throwaway card, put a bit of cash there, pay for what I need, and then delete the card.
It's a shame credit cards don't offer the same thing (Chase is able to list them all but provides no contact information or ability to revoke authorization)