The Lifespan of an LP?


How many times can one play a new vinyl lp before the sound noticeably degrades? For the purpose of the exercise, assume one takes decent care of the record and has a properly set up and maintained, good quality deck and stylus. My system has been taking quantum leaps in quality over the last three years and I find myself buying more mint and near-mint vintage  records on Discogs and audiophile remastered records from MoFi etc. Thanks!
heilbron
There is a huge factor over which we have no control -- the vinyl compound itself. Most of the plastic today used in records for the US comes from Thailand, I believe, and like a custom butcher that sells to restaurants, can make a proprietary compound that is a "secret." You won’t to my knowledge get the exact details and what could you do with the information anyway? In terms or residual noise, consistency of materials, there are a lot of other variables too.
That old MoFi JVC Supervinyl was the bomb. I played some of those records to death, and while in many cases not my preferred pressing now, those copies, which I had from the ’80s, are still quiet, tick or noise free and no apparent degradation over a more than "good" system.
Luck of the draw in some cases-- certainly today when you see what comes out of places that I’ll refrain from naming. (Rainbo-- stuff was horrible, even though they could make a good record; now out of business).
People swung to Japanese vinyl during the oil crisis and through the death of vinyl in part because of the quality coming from there- safety copy or different EQ be damned (On some music it's very neutral but that’s a subjective factor too).
Old vinyl- all over the place. I’m more interested in what it was played on than how many times it was played. But, don’t know that either in most cases in the used market. I have old records that play great and have seen some play here over the years- copies I know I’ve had for a long time. In some cases, the stylus may be in contact with a different part of the groove, and that may make a difference too, as would how your entire phono section works together. See @Atmasphere re noise and phono stages, loading, etc.
And some vinyl is just inherently noisy from the get go- and also very immediate in its sound, like you get one with the other, but that’s not a consistent truth either. It’s pretty much case by case, and every copy of every record has a history.
I had new copies of one record that played clean the first time, but afterwards had ticks and pops. Record had been effectively cleaned to beyond archival standards. I think it was just a soft compound, but I don’t remember cueing individual tracks, which I certainly did back in the day on records I’ve had for years, and they still sound great-- fresh cartridge, high end table, etc.
Short answer: depends.
Still have the first album I ever bought. I think it was in '69 or '70, has definitely lost some of its fidelity but I still enjoy listening to it.
These are all great stories. Thanks for sharing your experiences! I never thought records could endure like this. I always thought over the years, regardless how wel maintained they were, something would be lost. This discussion has prompted another question for me but I save it for a separate topic. 
I just purchased an LP from 1959 Porgy and Bess ( Lena Horne and Harry Belafonte) as it was recommended to me by my good friend Steve Guttenberg and it’s phenomenal. 62 year old used vinyl in stereophonic sound and it sounds like these two two brilliant singers are in my living room. Literally once you hear this, you will understand why digital is meaningless. 
I have many LP's I bought from 1964 onwards, 57 years, still sound great.
If you pay attention to cleaning and if your tonearm and cartridge is set up good they should not wear.
I am not guessing about this, it is my experience. In fact as I upgrade they are sounding better than when I first bought.