Can I offer a further bit of analysis which I don't think has so far been mentioned?

When folk rock came in around 1970 - bands suddenly needed amplifying. Then - everyone needed amplifying.

I went to hear (amplified) Frankie Gavin and Tim Edey last week in a room which I can remember as unamplified when it was used as a regular folk club. (They were magic by the way!)

So bands had to travel with their own gear - or the club had to supply it. Most clubs didn't/wouldn't as artists began wanting amplification.

In other words once folk clubs needed amplification - they gradually folded - well at least many of them did.

Now here is a thought - with modern equipment, miniature and not so bulky and expensive and clearly judging by the numbers of people who come to festivals, maybe clubs will grow again!!