While updating HTML/CSS/JS file in CRX DE editor, it should highlight the syntax. It will give a better understanding and help to navigate quickly to the particular element of the code.
Current/Experienced Behavior:
Currently, it is not highlighting the syntax for any of the files
Improved/Expected Behavior:
at least a basic syntax highlight should be there.
Environment Details (AEM version/service pack, any other specifics if applicable):
My thoughts on it: I don't think that Adobe will invest effort into CRX/DE, especially not into features which you would consider development features.
Development should happen in a full-fledged IDE (whatever you want to use), and not in CRX/DE. Whenever I do some JSP hacks in CRX/DE, I copy&paste the full code from my IDE into CRX/DE.
Another observation: In the past there was even functionality which allowed you create bundles in CRX/DE, and it has been removed for good reasons.
If you look into the AEM as a Cloud Service feature list, you can see the Repository Browser, which provides you a read-only view into the repo, for many cases removing the need to use CRX/DE. My guess is that CRX/DE will eventually be removed from the AEM as a Cloud Service environments (but probably not from the SDK, it definitely has value in development, but not in developing code).