While it is possible to work with containers to run programs with files on the host, it's just much more convenient to be able to run programs without dealing with mounting issues.

For an editor, maybe, for the files that you mount. But when e.g. a language server or IDE is involved, they need access to the tools that are now only inside the container. And then there's the shell itself, your shell history, etc.

On Linux absolutely, the IO latency on MacOS with mounted volumes is atrocious. Using a nix environment also avoids the weird edge cases I tend to run into with volumes mounts and file ownership and such.