In my opinion one inherent property of languages is how large the largest program is that can be written in those languages. There's languages that work well for short programs. Bash, perl are examples on one end of the spectrum. Then you have things like lisp and Python where the largest programs are a lot larger already, but still hit obvious limits. And then you have the languages that support really large codebases. Java, C++ are ones currently in use.

There's new languages where it's a bit of an open question still where they lie on the spectrum. Go would be one of them. I'd guess somewhere between Python and Java. Javascript I would argue is between perl and python. And Rust ... well ... good question.

An office suite is a gigantic application, which will need feature upon feature upon feature upon feature. If you want it working on the web, I'd propose something like C++ and WASM.

Wt actually isn’t terrible, with the added benefit of being able to leverage the enormous c/c++ library ecosystem. Also, it can be quite fast if you care for it to be.

Edit: also appears to be based in the eu, how fitting for this thread.

https://www.webtoolkit.eu/wt