Hi. I am glad you enjoyed it. That is this collection's primary purpose.
The true history of the OSR is by now very tangled and confused. This is a very comprehensive look at it if you have 9000 hours.
https://osrsimulacrum.blogspot.com/2021/02/a-historical-look-at-osr-part-i.html
Simply put, it had an OD&D/AD&D language before it had a B/X language. I would agree there is dilution as a result of an influx of newcomers, but the main problem is these newcomers have not been habituated or 'civilized'. Increasing the pool should increase the amount of good material that is coming out also. This, I think, does not occur in the same measure that it used to.
I think the decay is exacerbated by having neither a culture of practice nor a unifying system which serves as an anchor for that culture. Without it, you go back to square one, stumbling in darkness, endlessly re-invented the wheel. It is a precondition for transcending Sturgeon's law, rising out of the primordial chaos.
I run a fairly popular review blog. I've criticized everything from uber traditional AD&D tournament modules, 5e campaign settings to more Artpunky material. I have a preference, but I've given very positive reviews to works like Deep Carbon Observatory, and negative reviews to, say, The Seven Shrines of Nav'Qar which I find too traditional. My goal is not to destroy innovation. It is to refocus creative energies and encourage engagement with the subject material.
This year it is high level D&D. Keep an eye on the blog if you would like to know more. And happy gaming!