Speakers are made up of various materials and devices. I’ve found that the moisture content of a component is a big factor. As components dry out things happen such as materials turning to dust, convert from solid to goo, leak, or become brittle. Foam, plastics, coatings, capacitors, etc. We just serviced a pair of 64-year-old speakers. 5 of the 6 drivers, AND the crossover components were still operational. Not sure if the "blown" tweeter was due to abuse, or aging in this case. I’ve got a single Klipschorn from 1958 in the loft what works fine, with the correct drivers intact. I don’t know the complete history of the speakers.
My hand-built speakers are made up of 24 drivers (rubber surround mid/woofers, soft dome tweeters). I had them when I met my current wife 34 years ago. The speakers (and marriage) are hanging in there.