Here is what I think IDEs need to do different in the 2020s:
- configuration needs to be in human-readable configuration files, not obscure XML configs that can realistically only be edited through UIs.
- how to build the project needs to be completely decoupled from the IDE
- compilers and language services need to be separated from IDEs. LSP and automated refactoring tools using the same infrastructure as the code that's doing code completion makes sure that everything is consistent
- emphasis on input latency is needed for editors to feel snappy. Lots of full blown IDEs are not great for editing text.
edit: typo