Ex-PagerDuty here. Without weighing in on the criticisms of pricing and innovation with the product, I will say that the value of PagerDuty is its reliability in notifying you when it receives a signal from a system. Rebuilding the product isn't just asking an LLM to spit out a web app to do scheduling, it's in the notification pipeline (SMS, email, push notifications, Slack), maintaining all that and mobile apps too.

Just like Uber itself, this is one of those "I could replace this in a weekend" things that doesn't actually pan out that way.