Why the apparent lack of live soundboard recordings from Pink Floyd?

[BMF Effects]

I've been casually collecting ROIO's for years and for the most part Pink Floyd soundboards seem to be few and far between. There are some great BBC recordings and a couple DSOTM shows that sound great but nothing from the Animals tour (would love clean versions of "Raving and Drooling" and "You Gotta Be Crazy") Just surprising to me that more soundboards haven't surfaced.