It's telling that most instructions deal with the Javascript toolchain and not Rails itself. And let's hope that everything works and none of the 2000 imported node_modules blow up when this tutorial is 3 months old. I'm looking forward to Phoenix 1.6 which ditches Webpack for esbuild. Every step away from the insane churn of the modern frontend world is welcome.
Rails will soon default to using ESM instead of Webpack. https://world.hey.com/dhh/modern-web-apps-without-javascript...
Still, there's the need to install NPM packages. You can use Skypack as a patch, but ideally you should be able to host all of your JavaScript. I guess you could use `npm` and manually link to those files in your configuration map, there could even be an automated Rake task to do it, but I don't know if that's the direction DHH has in mind.