It's not too bad now, set up a Node environment and there's first class support for using vanilla esbuild or if you want to go without Node entirely there's import maps and lots of goodies at the Rails level to help you manage your JS dependencies. Technically Webpack is still supported too but it's vanilla Webpack instead of Webpacker, that's all part of the new https://github.com/rails/jsbundling-rails abstraction for using a number of different JS bundling tools with their stock set ups.

Personally I went with the esbuild + tailwind combo and it's been smooth sailing. I have an example app here https://github.com/nickjj/docker-rails-example.