The concurrency design in Haskell is cool, though I gotta admit that I don't find it much fun to write.

It's not because the language is "hard". I remember when I first learned Haskell a million years ago I thought it was the coolest thing ever because I had never seen anyone work at that abstract of a level before, especially in a compiled language. I got to understand the theory well enough and I know how to write a program with it, but the entire language kind of feels slapped together to me. Every time I've written anything in Haskell, I feel like I have to do a million compiler extensions, or rely on third party libraries' liberal use of Template Haskell (e.g. Lens) to make the language feel anywhere near "modern".

Yes yes yes, I know this is a complaint about GHC, not "Haskell", but given that GHC is basically the only Haskell compiler that gets serious use I don't think it's weird to conflate the compiler and the language.

Template Haskell is actually pretty cool. Using it to generate lenses in a type is a perfectly fine use case (of course hand-writing lenses is just one line anyways). Running computation at compile time is really a great feature; people rave about comptime in Zig but of course Haskell has had it earlier.