As we've discussed here before, there's not much room to improve a 97% efficient chain drive, and giving up variable gear ratio is a big hit in transferring the rider's muscle energy into propulsion.

https://cr4.globalspec.com/thread/121433/Cool-New-Bike-Drive-Train#comment1251708

I paid $99.00 USD for my single speed cruiser bike when I retired. I ride it every day for 2.5 miles.

I was given a fairly expensive 24 speed mountain bike. It shifts and rides like a dream and has disk brakes so it stops fast.

I ride my single speed cruiser bike every day for 2.5 miles. I'm going to give the expensive bike to someone who wants it.

Don't fix it if it ain't broke.

Yes. I remember my grand-dad's chainless bike using similar transmission, except I would guess it had only one speed gearing. That was in the 1940's so guess it was manufactured well before that.

If they can add a compressor I have a way of getting it off the ground.

I remember some single sprocket 3 speed bikes that used a shifting gear transmission inside the rear wheel hub. I wonder if that was ever combined with a chainless drive.

I still have an old Raleigh in the garage with the 3 speed hub at the back, and a built-in hub 6 volt generator (still functional) at the front.

The first derailleur in our city (central Ontario) showed up around 1964 (I know they were invented before that). It was owned by a fellow high school student. It was interesting because it still had the old internal three speed rear hub, but with a 5 sprocket external derailleur, giving him 15 gears total. Boy, were we envious! I have never seen that set-up since.

Forget bicycles, where's the flying chairs?