Futures/promises do form a monad. async/await is not a monad since async and await are not values, functions, or anything really. If they're implemented on top of futures/promises then async/await are like a hamstrung version of do notation that only works for one particular monad.

Also async/await is not really full continuations, it's a very restricted subset of continuations (which is good, full continuations are incomprehensible).

"async/await is just the do-notation of the Promise monad" https://gist.github.com/MaiaVictor/bc0c02b6d1fbc7e3dbae838fb...

In my experience Haskell significantly outperforms C++ on real-world business problems with realistic development effort (as opposed to carefully tuned microbenchmarks). I do think laziness was a mistake (to the point that one of the biggest industrial deployments uses a strict variant instead). I've spent most of my career doing work in Scala that's very much real-world, so as far as I'm concerned all the people talking about these things being academic or overly abstract are talking crap - I use this stuff every day, and whenever I've tried to take a shortcut (e.g. define a slightly law-breaking monad instance, abuse some mutable state somewhere) I've come to regret it later.