This is purely my point of view.
TTs and road racing should use basically the same bike. Since tri-bars and disc wheels are banned in road racing, they should be banned in TTs as well.
When tri-bars were used to first win a race, they gave an advantage no other rider had, therefore the result should have been declared null void.
Tri-bars changed the riding position; holding the bars with your hands is fundamentally different from resting on your elbows.
There is a before tribars era and the now tribars era, that is a break.
The first time disc wheels were used, I think, was the Moser hour record in 1984. They should have been banned because they gave Moser an advantage that Merckx in 1972 didn't have. But the UCI probably didn't because of commercial interests, which also applies to Lemond and tribars.
Road racing is not about "progress", it's a person to person sport, each rider in a race should have the same bike in performance, it doesn't make any difference if all or none of the riders use tri-bars or not. In timed events, eg TTs, records, there should be continuation from previous rides.
Tribars and disc wheels do not translate into useful items for non-competitive cycling. Whereas other stuff like clipless pedals, more gears etc can be useful for general cycling.