"It's interesting how many companies simply shut down service rather than say give a warning and wait for a response (or at least start a clock)."
I'm sure many people have started their companies firmly convinced that they'll give plenty of warnings and never automatically shut anything down.
The problem is, you rapidly discover that doesn't scale, not even on a human level. You send your notice. 48 hours later, you've gotten no response. If you act now, it isn't materially different from your point of view as if you simply acted right away.
Also, in a cloud environment, even Digital Ocean, as many people have learned the hard way with leaked credentials, you can rack up charges faster than the relevant humans can even conceivably be notified. As the hosting company, you can't just let abusive or accidental usage go. You can refund their money, but that's still resources of yours that went to something that failed to produce revenue rather than something that did; you can't absorb that indefinitely.
I'm pretty sure you'll inevitably discover that you have no choice but to put automation in.