The Lifespan of an LP?

Yep me too. May records I have are from the fifties a new sixties and still sound better then many reissues. Lifespan? With something like 5k, until I’m tired of hearing it

Like 199a6 I have used Last Record Preservative and Last Power Cleaner on all new records worth keeping since Last first appeared in the late '60's or early '70's.  Cleaning a new record with Power Cleaner often removes a layer of "grunge" that new records have, and the Last Record Preservative (which claims to prevent 50 playings) lives up to its hype.  I can take a record from 1970 and it can sound brand new (better than new, actually, because it was Power Cleaned first.)  I have never bought a wash machine because I have never felt the need for it.

When cared for properly, likely far longer than your lifespan. 

 I'm 69 years old.
I bought the "Best of the Animals in 1965".
It still sounds good now when I play it on my LP12.
We had a Magnavox console stereo growing up. Luckily, it wasn't trashed with that old heavy tonearm, and cartridge.

Don't play your most valuable records at all. Put the music on tape and leave the records alone. Then they will last maybe for centuries.