So you are mainly interested in GUI applications for laypeople to use, right?
I think there is a simple reason for that not existing as much as you'd think or hope: writing a GUI framework from scratch is a lot of work. So what people do nowadays is try to bind to existing libraries, GTK, fltk, DOM, Qt, etc...
But that comes with a cost: Those libraries need mutation to work, and therefore feel alien, and pointless to use in an immutable functional programming context. Most of your app would need to live in `IO`, basically. Why use Haskell at that point?
But there is a way to tame this beast: Functional Reactive Programming, or FRP for short. This way one could compose pure functions, events and behaviors that drive an underlying mutating GUI library in a deterministic way.
reflex-frp comes closest to this in my experience so far, which with reflex-dom and jsaddle is able to drive a browser window through a low-latency, local websocket connection. Meaning that you can, for example, run native Haskell code and only run a very thin layer of JS to interface with the DOM. This way you can build apps that have a GUI window on the desktop (e.g. with WebkitGTK) and is much faster than Electron.
You can also build the same reflex-dom apps to Android and iOS, and I've heard others remark that due to the native code doing most of the work in the background it is able to run faster on an ARM CPU than the comparable JS on the desktop. Though I've yet to try this myself to confirm.
At any rate, I think we are getting very close to a tipping point where GUIs become easy enough to write and then you'll see more and more written with Haskell.
Edit: Another potential "attack-vector" will be WebAssembly: Instead of compiling Haskell to JS via GHCJS, you could compile it to wasm and use it on websites' front-end much more performantly. When there is a working Haskell-to-wasm compiler, (hopefully soon) you'll also likely see more and more GUIs written with Haskell on the web.
I've written and deployed 3 applications written with Yesod so far. I also have some experience with Ruby on Rails. I'd say the two frameworks are rather on the same level of abstraction and similar in terms of productivity in my experience. And I like the type safety Yesod is able to provide, e.g. even for routes.
https://webchat.freenode.net/?channels=##nvc
It's the ##nvc channel on Freenode.