Yes, there are an enormous number of old LP’s available for old guys like us (pardon me if my assumptions about all ya’ll are incorrect ;-), but for the format to have an enduring future, new music has to available on LP for younger music lovers to buy.
Long after the CD had replaced the LP (throughout the 1990’s), I continued buying new releases on the latter whenever possible. And the price of used LP’s then was like that of CD’s now---dirt cheap. I am still finding Mint- copies of LP's from the 60's/70's/80's for five bucks or so.