A couple of things here. First, that's a fabulous hoard of parts and radios.
There are others , he's by no means the last. There is plenty of information published on the internet for anyone in the future wishing to make an old radio viable again. The everyday AA5 ( 5 tube , the most common) most people can be instructed and electrically have it working with about 3 to 4 hrs instruction, not 50 years he has romanticized in the video. They are all the same, there are not many variations of the Superhetrodyne and changed little until the 1960s. Even after that , only components , the basic principles didn't change. Of course some radios will present more advanced technical problems to solve, this is fairly rare. Because most were abandoned in working condition for newer ones , then all together when the transistor came along , there is a standard procedure (replace power supply capacitors and any paper capacitors) . If it doesn't work after that there is usually only one thing wrong that caused radio to quit you must find . Once you break down the radio into sections in your mind, ( he mentions this) finding a problem is not an educational leap as they are fairly simple. So I dispute there won't be someone always out there that can fix one.
Second, it's not possible to support yourself fixing them. The cost of shipping heavy chassis and an hourly rate equal to today's market makes the cost more than they want to spend for most people, unless they are determined to have one and plenty of disposable cash. He would need to be pulling in several hundred $ a day to claim it's more than a museum .
So, it's not that there's no interest in vintage radio , there are time and economic factors here. This has been shown by others who have tried including myself. I don't believe repair is supporting his business functionally. It is a hobby or passion more or less.
More power to him however, he is the big league of whats left, but when he is gone all of it will constitute a collectors bonanza. There are people salivating over the article pictures as if it were porn , I guarantee.
I personally have about 50 vintage radios I fixed myself , and about half a wall of tubes like in the picture. E bay and it's ilk drove down the price of the remaining stocks of tubes ( which is 100 times more than anyone thought prior to internet) except for the rare ones which subsequently went through the roof. I recently sold a single tube for a lowball price of $65, 2 hrs after listing.
I love it though, thanks for the link, I'd love to visit with him.