I’ve said this before, and some here don’t like it, but the rate of innovation in commercial aviation during the last 60 years have been pretty pathetic compared to the incredible innovation of the first 60 years (from the Wright brothers in 1903 to 1963). Sure commercial jets are safer, and there have been improvements in fuel efficiency and auto-pilot tech and a lot of that, but from the passenger side, it’s been very stagnant. I’m not flying to Europe any faster than I did 50 years ago. I get it that government regulations ( sonic-boom rules specifically) have limited what the aerospace companies can do. But, still, it’s been disappointing.
The efforts have been for fuel economy, which has required much higher engine temperatures. That has required new engine materials.
The engines from the 747 our family flew in 1972 to Britain is nothing like current engines.
Just the turbine blades. Early days jet engines turbine blade was a steel forging. Now its nickel based alloy, single crystal structure. Each blade on the turbine costs $20,000+ and there are 3 turbine wheels with ~ 100 blades each.
Compressor blades are cheaper, maybe 10K but maybe 6 turbine wheels.
So each engine has ~ 10 to 12 million dollars in blades, and that’s not the whole engine. Just the blades.
Part of that can be explained by there being a lower ceiling on aviation development compared to other technologies.