[et-al]

Standards always evolve and ultimately if the larger companies like Shimano, SRAM, or Taiwanese OEMs don’t adopt them, they’re a moot point.

Bicycle chainrings are the perfect example. There are established mounting patterns, but since the late 90s, Shimano’s MTB division and Campagnolo loved introducing proprietary BCDs.

And disc brakes have an established "International Standard" mounting standard, but no one builds actual I.S. mount brakes--it's either post mount or flat mount. (Yes, post/I.S. are practically interchangeable due to the adapter.)

Lastly for something as simple as a derailleur hanger, you figure there may be 5 or 6 different models to choose from, but nope: https://wheelsmfg.com/derailleur-hangers/derailleur-hanger-w...