The most important outcome for me when I did this (for 6 months) was my own webapp generating infrastructure, modules for common things with a whole lot of scripting to integrate 50-80% of all features (payments, chat, onboarding flows, landing page templates, dashboard templates, checkout flows, profile creation, etc.) depending on the app. Of course, building this infrastructure took about 4,5 months to put togethe…
Well if you're a Python person, Django is amazing, and if you're a golang person Gin Gonic is amazing. Not everything webapp is Rails, although Rails is wonderful for prototypes. The only two very large rails sites I was ever consciously aware of were Twitter (now all java) and Groupon (now mostly node).
I was only making claims for rapid prototyping. I still contend for prototyping there is no better framework than Rails. From the start DHH designed Rails specifically for prototyping of web apps, and your custom prototyping infrastructure will sit very nicely on top.