A good high quality electrolytic capacitor will last 10-15 years with almost no variation in its rated specifications. Beyond that, you'll get degradation at various rates. They all start to dry up or have electrolytic chemical degradation, impacting the ESR, resistance, leakage current, high reverse voltage, etc. Lifespan of in-service electrolytic capacitors depends highly on heat and design of the circuit. If they're operated cool and below 80% of the rated voltage, they'll last longer.

However I have a large supply of new old stock high quality capacitors (25yrs+ old) at work that I test every once in a while when I grab a spare for a project, and I find that many of them are right at the edge or below their rated specifications and have to be thrown in the garbage.

The capacitor plague was a whole different issue with accelerated failures due to improperly formulated electrolytic, and those capacitors should all be replaced.