Things *have* changed dramatically - you can install hls via ghcup, or clone+stack install.hs <desired-version>. For vim enabling it is literally one line for your lsp client. For vscode you don't even need to download/install it - there are static executables and installing the extension is enough.
Looking at
https://taylor.fausak.me/2020/11/22/haskell-survey-results/#s2q1, stack is by far the most popular way to manage GHC installations. If I read
https://github.com/haskell/haskell-language-server correctly and I don't want to compile hls for myself, I have the option of either using ghcup or manually downloading the prebuilt binaries. I have never used ghcup before, and I don't intend to do so in the future (stack user here ;-), but I gave it a try. It took me some tries and modifications to the script to install only hls (no need for additional GHC/Cabal installations) to an XDG-conformant path. Downloading the wrapper + some hls versions manually from
https://github.com/haskell/haskell-language-server/releases is definitely doable, but still a bit fiddly. I guess Vim people need to do the same, only the VS Code extension does things more automagically.
In a nutshell: Much better than before, but a far cry from a one-liner for the most common installation/IDE combos. There is probably not much missing: Only a simple script to install the wrapper/all hls versions into an XDG-conformant path (optionally selecting only a subset of the versions, but this shouldn't be the default). Coupling this to ghcup doesn't look like a good idea, this tries to set up too many unneeded things, at least I wasn't able to figure out how to download *only* hls.
It also fails much less often, automatic setup configuration is improved, and features are growing at a steady pace.
Great! :-) I think I'll give it a real try soon.