It works, where the common case finally works, using an approach out of a set of approaches (libraries, tools etc).

It make sense, where the software works using the approach specified in the design doc, and the code can be easily understood (via design doc, good test coverage, organized code).

It can change, where the code owner/team can easily change the software based on change in requirement. Everything that was ever built deteriorates, so simplicity is the only approach that gives a fighting chance to stood against the test of time. "Just Enough Engineering" - https://www.quastor.org/p/how-whatsapp-scaled-to-1-billion