Although the stakes aren't quite so high , this is also true in fly fishing and fly tying. Beginners especially need a lot of support on gear and technique. There are a lot of great resources and instructors, but there are a lot of charlatans and it doesn't seem to me like the bulk of anglers are equipped to tell the difference. I'm not saying that there's anything wrong with a friend helping someone to get started, but when money starts changing hands I think there's an issue. I recently did a 1-on-1 zoom class with a guy who had recently paid someone else (someone with quite a big social media presence and a clutch of scycophantic followers) £120 for a 90 minute online class, unfortunately I spent a good chunk of our class fixing things that were flat out wrong that he'd learned in the other class. For example, he'd tied some palmered flies and couldn't understand why they kept falling apart, so I asked him to tie one and I watched, the "teacher" had told him he had to wind the rib in the opposite direction to the hackle i.e. the hackle is wound away from you and the rib is wound towards you over the top of the shank so the rather than tying the hackle down with each wrap of rib, only the first turn was lightly catching the hackle and the rest of the rib was spiraling between the hackle. I saw the recording of the class and it wasn't a mistake made by the student, the guy who was charging over a tonne for the class did it on 3 different flies. It's scandalous and I hope my student gets a refund. I've recently seen the same guy giving reviews on lines and rods despite being unable to sat much more than the length of himself.
Yes there are accrediting bodies that can offer some assurance to the customer, but this is no guarantee. I'm not a casting instructor, but I've had good and bad experiences over the years with instructors - one of whom was awful, despite being AAPGAI accredited. I've also had great lessons from CCIs who are no longer members of any organisation. It's not a guarantee, but at least if an instructor is certified you should be able to count on them having enough knowledge and skill to help you improve. I'm not a member of any of the fly tying bodies. I once considered getting a certificate, but then I saw some flies thet were tied by a GAIA or AAPGAI instructor and decided that I wasn't going to be examined on fly tying by an organisation that would pass that dross. Then there's the Fly Dressers Guild, to pass their tests -at least when I last looked at it- you didn't even have to tie in front of anyone, I know someone who was tying spiders for theirs and tied about 2 dozen of each pattern and sent off the best 3 of each fly.. He passed it, but either he's not really good enough, or if this is normal practice the expected standard is possibly too high. I'd put less stock in a fly tying accreditation when it comes to booking a class than a fly casting one, but again I'd hope that at least it would be a sign that someone would know the basics.