In my mind, an IDE needs to be able to read all the files I can read myself, it needs to be able run arbitary tools like compilers and linkers then run the resulting compiled code, it needs a debugger that can attach to running processes and mess with them, it needs to be able to pull from the language's package repository when you ask it to, it needs to talk to your git server when needed, it needs access to your SSH keys to do that. About the only thing the IDE doesn't need is to run as root - and if you're working with Docker it basically needs that too.
The idea of an IDE with pluggable language support safely running plugins from untrusted sources? I can't imagine how such a thing could even be possible?