Retries aren't the only option if you control (or can at least influence) the client. Fallback sources and sane (or customer preferential) defaults are some additional options when the primary source of truth is unavailable. Both of these bypass thundering heard situations where recovery can be difficult even if the application returns to full health.

As a concrete example, when I worked at a large online retailer, we had to check certain customer properties during checkout. In the optimal case, we went to a service which fronted a consistent, transactional database. If that service failed or timed out, we had the option to hit a fast cache which generally was only a few milliseconds out of date. Finally, we could use less authoritative data that came from the application earlier, and if present, would always be in the customer's favor. That made it unlikely that our service ever appeared "down" regardless of the state of the dependencies.