First, let me say - I think the vinyl boom has about 10 years max to go.
A combination of forces here.
First, prices have gone way up for new vinyl. The reasons for that I have discussed here several times.
Second, streaming has way, way overtaken physical product. labels don't want physical product. They only want streaming.
Third, the initial vinyl revival was fueled by older white males with serious disposable income who gravitated towards very conservative fare from their heyday - the 50's and 60's. The other end was fueled by younger people and basically gravitated around the metal market, where there was a major boom in vinyl. Those older white males have their collections now. The way to keep them buying is only to keep regurgitating Kind of Blue and The Doors, which for the moment, they will keep on buying. One-Steps, SRX, all that bullshit, are all aimed at this demo for whom price is not an obstacle. MOFI was once exciting, a discovery every month. Last MOFI I bought was Procol Harum's A Salty Dog. But that is reaching it's limit, as that demo dies out or gets to the point where enough is enough.
Fourth, the market is saturated. Too many releases. Too much product being pumped out. It's getting commoditized - again.
Fifth - younger people - in their 20's, it's only streaming, except for a few who view vinyl as a way to stand out from the crowd and be different. In their 30's and 40's, they all started on vinyl in the last 10 years or so, have a pretty decent collection, and are getting into buying a house, having kids, other priorities. It is coming to an end for them, or at least slowing down.
But - vinyl sales are still growing, although soon to approach a peak. From what I see, this has more to do with the older demo than younger, which is not a good sign.
When I returned to vinyl about 15 years ago, it was niche. Reissues were not the big sellers, metal was, and new indie artists. Classic Records brought the old folks out, and soon, MOFI got back into it. Speakers Corner was keeping it alive too, and occasionally AP got their feet in, but not in a big way. Rhino/Warners had one guy who was passionate about vinyl so they were in big from the start, but other majors were not. Kevin Grey was parked in a back room ar RTI, doing house mastering for whatever popped in, and forced to collaborate with Hoffman when he came to RTI. Bernie Grundman didn't even have a lathe anymore until Classic came knocking. This is how the reissue revival got started. There was no VMP. There were no One-Steps or SRX's. A Classic title - the premium product - sold for $30.
It was a product of passion, not a commodity market. There was no Discogs. No need - everything was pretty much available or could be found, and mostly at list price. You would go into a store and there were racks of Classic titles, MOFI's, Speakers Corner, Pure Pleasure and Rhinos. If something sold out, it took six months or over a year - and even then, could still be found. There were NO limited editions - or, they were all unadvertised limited editions, as the market wasn't huge.
That was the fun time to be into vinyl.
Then - the money got in control of the market. Collectors with money, labels looking at a high margin revenue stream. The growth in the market caused prices to rise for titles that had previously been easy to find for a fair price. Internet bullshit casued a rise in prices for original pressings, which in many cases were not all that great. Labels that had once been based on a purpose - to get more interesting music back on vinyl in great sound - MOFI, MMJ, AP, etc. - abandoned that purpose and became pure money grabbers. A few didn't - Speakers Corner, Pure Pleasure - and the only remaining major really committed to vinyl abandoned it, except for new releases. Labels found new ways to bring in a new type of buyer - the colored variant type buyer, who sought the exclusivity, perceived status and bragging rights - and were willing to pay more for that. The original type buyer, who fueled the vinyl revival, recoiled.
As a person who has worked in, and studied, marketing for his whole life, these are all signs of an industry in the throes of it's last cash grab opportunity before it all collapses. When it becomes a fashion market, it is nearing the end. It isn't so much about music anymore, too much of the market is about collectability, and the industry feeds that.
Personally, I can't wait for it all to cave in on itself. The music industry has a history of doing that to itself. Then, the only people left will be the music lovers who have a passion for vinyl as a superior music reproduction and archival format, and not because they have a limited to 250 worldwide splatter colored variant or a $100 45rpm box set of a warhorse they have bought 10 times already.