Yes they do have a role and they play it with all the variability and individuality of the people who are prepared to put the effort in to run them.
I have never run a club but have served on the Wellington FC (Inc) committee in NZ and a few Festival committees. It is not a thankless task but can appear so.
I prefer sessions and SAR but there are plenty of people who do not perform and FC's entertain them by and (notso these days) large.
cresby.com gives you an idea of the breadth of opportunity in my area for participating &/or being entertained.
Try folk clubs in other countries - I can speak for Canada and NZ and outside of the cities alternatives can be 50 miles away if your local bash is populated with people you can't empathise with. Here in the UK that distance is far more likely to be 10 miles or less. If it is that popular it must be serving some purpose.
AND admittedly the emphasis does appear to have shifted to festivals where it is encouraging see young people - and talented curse them!