Parcel is easy to use (as long as you stay on the golden path), but I have a hard time calling it simple.

Automagically installing dependencies that it fails to `require()` seems way out of scope for a bundler. Or managing Rust toolchains. Or a bunch of hard-coded rules that hard-exclude compiling stuff in `node_modules`. Unless they're in symlinks (presumably for Yarn workspaces?). And so on.