I still have, and could use, a Primus 71L white gas stove I purchased fifty years ago. Every twenty years r so, I replace an interior wick and a small o-ring. It has served me well when a stove was critical and I know it works, and its idiosyncrasies.

It has been superseded by a MSR Pocket Rocket (lighter and simpler) which has been my principal stove for about a decade.

Use your gear so that you know it. You will be glad you did when it is crunch time.

Of course, if you want a stove that is truly immortal, get an alkie, something like a Trangia. My oldest Trangia is only about thirty years old. It will easily outlast me unless an elephant steps on it, an event I would not survive either.