[simne]

I don't agree. From my exp really big problem, when you can't easy see borders between parts of project, and this is case with React and many other fullstack envs.

From other view, yes, it is not good, when for example on front you use strict typed lang and on back dynamic, so need to constantly do conversions.

So need some reasonable combination. Traditional Java+JS is looking reasonable. JS (front) +Python (back) is also reasonable. C backend from my view is weird, so should be some intermediate lang, for example Lua.