Field guide
Prove the state customers feel.
Stripe is good at delivering events, retrying failed deliveries, and showing delivery status. That does not mean your product finished the business workflow. The risky part often happens after the provider event is accepted.
A safer billing monitor starts when the webhook is accepted and closes after the local result is true: the subscription row changed, the entitlement changed, the customer-visible UI matches billing state, and any recovery alert fired if the chain disagreed.
The alert should describe the missing outcome. Not "webhook failed." Not "Stripe event received." The useful incident is: "Customer access did not change after Stripe event."