How long should high quality speakers last?

After owning Revel Studios (a very highly regarded loudspeaker in the early 2000s) for more than 20 years, I decided it was time to replace them even though they still worked as well, I think, as when they were new. So, why?

Comparing my Studios with several current state of the art speakers (and employing equipment/cables as similar to what I own as possible), it quickly became apparent to me that 20 years of speaker technology developments had wrought some real improvements in sound reproduction. 

Accordingly, I now own Magico A5 and am enjoying vastly improved clarity, soundstaging, and imaging.

@asvjerry LOL

My DCM Time Frame 2000s date to around 1987 or so.  I have owned them for seven years and the still sound crazy good to me.  Given the relative rarity of the pair I am reluctant to do much work.  It is also the complexity of the design.  Twin transmission lines for the two woofers.  I have seen the TF1000 crossover so this must be much more.  The back panel comes off but it is (no exaggeration) 20 screws.

I also love vintage radios to talk how long a speaker can last.  A 1948 Farnsworth Caperhart 114N2 came into my possession recently.  These were the finest home entertainment you could buy.  In 1948 this model cost 1750.  It had Jensen's 5"/15" coaxial speaker the JHP-52.  It still sounds great to me all things considered with the  cabinet.

I'M GUESSING THAT oops sorry yelling that my ears will deteriorate faster than any other component I own so yay (?) for getting older.  BTW Youtube Bobs Capehart 41e 3 conversion if you want to witness a mechanical marvel.  20 record changer on the  Capehart that could play A/B, all A than B sides and shut itself off after a preset number of plays.

Interesting. I've never thought that speakers would deteriorate over time. I have a pair of TSM MMs that could be 20 years old ( Bought used). They sound just fine to my old ears, but should I doing some "maintenance"?

I have a pair of Snell Type C bought in the mid '80's and a pair of Large Advent Utilities purchased in the late '70s.  Both have had new surrounds installed years ago, cones are still in good shape.  They still pack a punch.  I use a 400 wpc amp with high dynamic headroom on the Snell's. 

If you're not buying them out of the back of a white van legit brands will last as long as we use them within their designed purpose.