If you want something to last, stop treating “still working” as the same thing as “well maintained.”

Something can be working perfectly well and be on its way to failing, since function tells you about the present and says nothing about condition. Using still working as your standard means you only ever act after the state has changed, which is the point at which options narrow considerably.

Separate the two questions when you assess anything: does it work, and what condition is it in. The second one is where all the useful decisions live.