I tried launching wdio with my global appium installation, which had a warning about a version mismatch of drivers, which has never been a problem for running tests.

2025-09-18T09:53:26.264Z ERROR @wdio/appium-service: WARN
2025-09-18T09:53:26.264Z ERROR @wdio/cli:utils: A service failed in the 'onPrepare' hook
Error: WARN

After resolving the warning the appium service started correctly.
The service should tollerate warnings or be explicit about killing the service when they occur.

I believe this is the line that should be modified: