Right. Why are we living with a notation which stopped growing about 150 years ago?

It appears you haven't studied one of the more recent books on notation. NOBODY 150 years ago needed to notate for a 64 note scale (in each octave), but ways to do it are now well enough known to be used by those who care. (NOTE: I'm not one of them.)

There are quite a number of other "innovations" either proposed by the "modern" composers or invented to make what they composed legible enough for others to play them from some accepted form of notation. Sometimes the orchestra may find the notations so "modern" that they have to buy the book (sometimes identified in a footnote on the back page?) but notation is NOT A STATIC THING that everybody has to do the same way.

Most of us do get by with the older traditions - because it works better than other methods of passing things on to others; but you can get pretty fancy if you really want to.

John