There are plenty of very basic things missing from the Text Editor:
- Horizontal scrollbar developer.blender.org/D4054
- Find Previous(search direction)
- Display output in either python console: https://gist.github.com/tamask/0593436d044bfedb21081e3d2d802833 blender.community/c/rightclickselect/vwfbbc/ or Info Editor: developer.blender.org/D9752
- Wrap on as default setting(continue search from top, who doesn’t want that?)
- Recent files: blender.community/c/rightclickselect/8qhbbc/
- Make unused sidebar space transparent(Region Overlap).
- Trim Trailing Whitespace.
- Intellisense: github.com/tin2tin/Intellisense_for_Blender_Text_Editor
- Text colors not aligned with 2.8+ colors.
- API: Get selected text as string: developer.blender.org/D6377
- Display line with error.
- Bug: The “line number highlight” doesn’t follow the cursor (caret) when selecting multiple lines of text: devtalk.blender.org/t/blender-ui-paper-cuts/2596/3530
- Save All missing.
Etc. but since the Text Editor is officially in maintenance mode, again, ensure the greenlight of the module owner before you invest in implementing a new feature or a fix in the Text Editor.