>>> Musical notation is not that hard. You have 12 notes, fractional rhythms, and various accents to embellish them.
Don't forget reading. The notation has to be readable on the fly by people who are capable of doing it. Proving this to be possible for a given notation system is a massive undertaking.
I still contend that it's not about traditionalism, but about practicality. Musicians don't want to suck. Changing instruments or notation means sucking for a long, long time before being able to use it at the level they already attained on the previous system.
I'm in this boat myself right now. I'm a working double bassist. As a lockdown project, I decided to get back into playing cello, after a 35+ year hiatus. I'm also trying to get up to speed on sight reading treble clef. I can tell that it will take me a crazy amount of effort on the cello to reach the level of the bands that I play bass in.
>>> It's also interesting to me that this hasn't been solved already by software. Notation is nothing more than formatting. We have dozens of competing data interchange formats, and it's pretty trivial to convert between them.
Then do it!
The good stuff isn't in the computer. ;-) Only about the past couple decades of literature has been digitized. Of that, vanishingly little is publicly available due to heavy handed copyright restrictions for sheet music. Some of the really good stuff was never even published, but hastily photocopied and shared.
My band's entire library, spanning a century of big-band jazz, exists only on paper, with the exception of a small handful of modern compositions.
>>> The fact that you shared an article about a professor creating a piano with such a subtle change like it was news speaks volumes to this problem. Imagine reading an article about a guitarist making a shorter neck guitar, then promoting a literal organization that petitions for variable-length necks!
>>> As for actual exploration on the topic, you can read about the Jammer Keyboard: https://en.wikipedia.org/wiki/Jammer_keyboard
>>> That thing can't control a grand piano.
There's no doubt that new instruments are developed all the time as I mentioned elsewhere in the thread. Consider the scratch turntable. It didn't even exist when I was a kid, and I suspect it would frustrate any attempt at notation using the current system.
New notation systems have been developed. For instance jazz bass parts that consist of a combination of notation and chord symbols didn't exist in the 19th century, and would have been unplayable by anybody from that era. The Nashville number system developed in the recording industry, sometime in the past century.
Instruments gain popularity in musical styles that don't depend as much on written music, such as folk, rock, and so forth. That's one way to deal with notation. Lots of adults learn to play without learning to read at all.
Amplification and electronic synthesis reduce the physical and acoustical demands on instruments, allowing the "user interface" layout to be detached from the physical production of sound.
When musicians do try something new, it's often not just to play the old music using a new technology, though that does happen. Instead, it's everything all at once. When the electric guitar burst on the scene, it ushered in new styles of music, and new ways of composing and communicating ideas that largely avoided notation altogether. Nobody formed a band of 19 guitars to play Glenn Miller charts. Well, maybe they did. It's amazing the huge variety of things that musicians are willing to try for the sake of novelty.