I’m not completely sure of that. The simplicity of a backbone app, plain javascript with no build, less/sass, early days node.js or old RoR apps is becoming increasingly elusive. Not a lot of modern apps you couldn’t build with those stacks, and most of the underlying technology is the same (http/html/css/js/sql/libuv/etc).
Saying this feels like advocating for a return to horse carriages though, when the right analogy would be the brief electric car era of the early 1900s, and React as the Model T.
I think what changed is that people sort of realized compilers and build systems aren't just those things, they are also tools. They can be leveraged for making your code work better, automatically, and they can help you.
The dream of scripting languages you can just throw somewhere is great, but in an IDE, they really struggle. They're editor languages - you can understand them without extra context and tools, but your level of understanding is baseline more wishy-washy.
TS embodies this. It directly trades off that scriptability and ease for... really nothing. The compilation isn't a side effect, it's the entire draw. People WANT a compiler, or, at least, something similar.
Ooof. No thanks. SASS can die a fiery death, and give me React over Backbone 10 times out of 10. I guess these things are somewhat subjective, but I don’t miss the pre-React days at all.
It is exciting to see what the ingenuity of the next group brings, even though some existing things are lost, but hopefully not forgotten.