As much as your creative sass added to the conversation, I asked a few concrete questions - specifically trying to understand composability, reusability of JS, and what the fellow means by "interactivity" given they claim you can do lots without JS.

They followed it up with a 1-word answer - pretty ridiculous if you ask me - and so I asked an expanding question so I could make my own conclusions of what the other user considers to be acceptable levels of composability and reusability.

While I could undoubtedly find that info myself, I am not the one advocating for Rails here, nor am I the one claiming using Ruby for browser interactivity is a strong idea, so it seems to me like the onus isn't really on me to go search this out

Not constructive.