This is really exciting to me. I've been meaning to try and get my head around how to start using ES modules with modern JavaScript stuff but it's tough because pretty much every tutorial assumes you'll be using Webpack. Snowpack looks like it might be the tool I've been missing.
I would also check out es-dev-server[1] from the open-wc.org project.
It's basically just a static file server that can automatically rewrite bare module specifiers using Node module resolution. It's the minimal transform you can apply to npm-installed JS modules that import dependencies via package name.
Yes, you get a waterfall of loads during development, but I haven't had this slow things down in practice, and once you get to development you can use Rollup to bundle modules, but unlike Webpack, it can bundle to standard module output.
