10 years should be enough time to get a working IDE and a good starting set of libraries, and my personal experience is that Haskell has neither.
Maybe you ran into an issue where there still isn’t a decent starter library, but there are actually tons of great ones out there that we’ve used to build production services. So I can’t say I really know what you’re talking about in general.
Language server support is a recent trend, and it’s being worked on for Haskell just like it is for everything else.
I don't think that's a fair take. Haskell started as a research language, and it's only in the 2010s really that it started taking off and becoming more and more practical. That's because people invested lots of effort in libraries like lens (and many others). Haskell didn't even have a strong build system until Stack popped up in the mid-2010s. Frankly these were bigger priorities. These things had to be solved first in order to transition Haskell from a research experiment in lazy evaluation into a real-world tool.
In 2020, outside of maybe dependent types, the community is probably more concerned with practicality and pragmatism than ever before. There's a huge focus right now on improved IDE support, for instance.