What is noteworthy about these albums that the artists would not have made them otherwise?

Pink Floyd’s next album had the cover and best song dedicated to saying how much they hated the record label

I'm not so worried about humanity's loss of peak works like these since I don't think any young band has it in them at the start anyways. What young artists need is an on-ramp and a way to stay in the business long enough to hone their craft and build a following while turning out a couple Pipers at the Gates of Dawn. Works like Dark Side and OKC are developed, not born, and we need that pipeline.

The problem was that the big companies had the good recording studios and the possibility to make records and distribution. This was very expensive.

Today are studios in abundance. And bands that are good are usually good connected and certainly know a good down mix engineer. Then they can distributed via Bandcamp.

Today it’s much better for artists who want to make music. The big record labels were just gatekeepers.