Our micro wave was exhibiting rust in several locations and it could not be cleaned up. My wife wanted a new one.
To our amazement, the old one was 30+ years old.
There were dimensional considerations that resulted in the very recent purchase of a new and current model of the old one. So, we got the new one.
Guess What? It is extremely similar in size and appearance but the operational considerations are a big improvement. Although seemingly the same, the new one is in fact better.
I had been replacing the new little ones about every 5 years. Currently on year 7