I was designing analog delay based studio effects back in the late 70s and early digital was not cheap and not that good, but quickly evolved to eclipse analog delays.
In the bad old days memory was the expensive part but digital word length was not very good, especially by modern standards. The 1 bit digital delta modulation was an exception where the sound quality could be quite good for short delays (high clock/sample) rates. Longer delays involving lower clock rates introduced users to a new (horrible) kind of digital distortion.
Lucky most of us have managed to forget about those old days.
JR
I remember the Loft 450 delay which used analog "bucket brigade" chips. I was a Loft dealer back then.