Up to a point. For clothing (eg, ballet stuff), trying it on is probably necessary and part of the excitement for the little dancers. You can’t buy goldfish online or ask about pumps or get pond plants on line. The Kirkdale bookshop works because you can browse more easily than on the internet (see what I did there?). Bell’s Kitchens presumably survives because of its service.
So there are certainly shops - and it depends how you define ‘hyper-specialist’ - that can survive and, by the looks of them, do well.
We have a fishing tackle business in Dartmouth Road??? That’s probably what I’d call hyper-specialist, whereas the shop in Penge sells rods, reels, etc. Again, stuff you want to get the feel of, talk about with the expert shopkeeper, etc.