Ruby on Rails is a fantastic base, but it comes with some defaults you as an solo maker don't need. At the same time it doesn't come with a lot of stuff you do want
: user authentication, common UI components, custom error pages, snippets for analytics, error monitoring and so fort.
Webpack is the way forward to add in great and modern tools. That's why Sprockets is removed by default.
Tailwind is an amazing set of Css utilites with a standardised naming convention. Wrapped together with PostCss you can create good-looking web UI real fast.