Software can be finished (Oct 2025) https://rosswintle.uk/2025/10/software-can-be-finished/
- There might be security vulnerabilities in the project's code that would endanger users if not fixed.
- There might be vulnerabilities in dependencies that required that the project updates to a newer version.
- If the project uses external APIs, those might have breaking changes, be shut down, etc.
- Last but not least, the environment itself that the app is running in might have breaking changes, e.g. the OS going out of support.
If a project really is finished but the author expects people to keep using it, then as a user, I'd expect that the author still does the above maintenance from time to time, so the project stays functional and safe.
Even I look at the last commit date as a proxy for "is this maintained". I wish GitHub had something similar to "Archived" for projects like these.