I agree it's quite annoying to set up an OCaml project, and all the Jane Street stuff makes it even more confusing for newcomers. But to be fair, it may be the case with other languages as well. I recently tried to learn some Javascript, and I spent some time understanding the tooling and package management (npm/yarn, bundling, transpiling, node vs browser, difference between javascript versions).
.NET you install either Visual Studio or just the SDK and everything just works. And it's not just the initial setup. It's the best debugging experience available. It has a robust extension system, though honestly, you don't need to engage it and you're still having an amazing experience.
For a while, I grumbled that it had spoiled me for other languages, the "fun" looking stuff that everyone talks about online. But as with all... rustic... experiences, it's only fun for the weekend. I wouldn't want to spend my entire life chopping wood for fuel, either. Even after spending 3 years fully in JavaScript land, getting very comfortable with all of the tools, it never really got "good enough". Years of effort and my dev experience was still worse than a default VS install. So I went back and have been loving life again.
VS installation is also a PITA if you have your C:\ on an SSD. The installer doesn't give you choice of what partition to install to (for most of its huge disk space demands) so you need to fake it with a bunch of symlinks. The VS team recognizes this problem but doesn't do anything about it, as follows from the comments on https://developercommunity.visualstudio.com/content/problem/...
Good question. Their libraries are robust and certainly useful if you want to develop real applications. I'm not sure but I'd say no because I think they add an extra level of complexity of a newbie. They are also quite opinionated which some people may dislike.
I talked about "confusion" because I suppose a newbie may quickly be confronted with this question, for intance if they want to follow "Real World OCaml" which is based on Jane Street libraries.
The tooling around OCaml has really improved a lot these last few years (opam, dune, core/async, merlin, ppx...). The downside is that it raises the bar for newcomers.
This seems sort of like comparing the complexities of learning German to a level of fluency with the complexities of learning English, differences between major variant forms of English, with a deep dive into the history of the English Language and its poetics.