Has the skill gone out of Fishing ?
I have taken my time to think on this question, purely because i tried to think how many situations in Fishing have turned up techniques that dominated the sport.
I don't personally feel that any of the skill has gone out of fishing, and i shall tell you why i think this way.
Almost anyone can learn to tie a Hair Rig, anyone who can cast a rod, can cast a hair rigged bait in to a water, and sit and wait for a fish to take the bait.
A good skilled angler, will, know when to fish, where to fish, how to present a bait, when to change rigs, baits, locations etc
You don't get them skills, from knowing how to tie a rig, or how to bait up a Boillie or a Pellet.
They come with experience, that also helps to dictate the sort of bait to use for any chosen day. How many huge carp have been taken on Sweetcorn / Maize (a lot i bet)
How many huge Barbel have been caught on Luncheon Meat (a lot i bet)
I think with the hair rig and the Boillie, it is not just the effectiveness of the Rig or the attractiveness of the bait, but, it is also the ease and the conveniance, of not wondering whether or not the bait is still on, or whether or not the hook is proud enough of the bait.
Is Fishing losing it's skills, No, it is only lost to those that never had it before, and never knew they needed it as it doesn't figure in how they fish or how they were taught to fish. Some Carp Anglers or other specimen Anglers have never used a float or fine lines and small hooks, they wouldn't know how, but they may still have caught 40lb fish, and they could probably out fish a lot of people for Carp.
For me the skill is not in catching fish, but, knowing what to do if you are not catching fish.
Not bad for a guy that can only see out of one eye, and that is blurred