PRS and similar organisations are copyright collection organisations operating under the Copyright and Patents Act 1988. In principle, they're a good thing, because they greatly simplify the process of obtaining the rights holder's permission to use copyright material. Instead of having to contact the rights holder every time you want to perform, record or broadcast their work and negotiate a fee with them (you still have to do this where holders don't belong to a collection organisation, and it is a pain), they simply charge the venue (or record label, or broadcaster) for a licence and pay the royalties out of that.

I imagine this works reasonably well for the mainstream music industry, but for those operating on the fringes (ie most of the folk world) it is a pain. PRS are notoriously agressive in their dealings with people who need a licence, and it's difficult to persuade them that you're not using music which they control. There is a lack of transparency about how they set their charges and what basis they have for levying them - often their answer is "because we say so". They are poor at consulting or explaining things to their members - we're expected to be grateful that they've done such a good deal on our behalf, but often this ignores that nobody gets anything if gigs are cancelled or venues close because of excessive licensing charges.

PRS is a not-for-profit organisation, but their 2019 accounts show operating costs of £101m, so someone is doing all right from it. £28.4m went on wages and salaries, and the highest paid director received £991,000.