[osdev]

I agree with almost everything you're saying. I'll just add that while Scala missed it's opportunity with Android, the big problem has always been a borderline dogmatic approach to pure FP by the community at the cost of simplicity. Scala libraries are generally complex and difficult to use (sometimes even for Scala engineers with several years experience).

Also, core FP principles are not that hard (immutability, expressions, HOF, functional error handling, pattern matching), but when you go full / pure FP, that is a steep cliff and an end goal in itself that has serious time /monetary/ complexity costs. The real goals should always be a healthy balance of reasonably fast business functionality delivery and a good code base.

[solicode]

There is that, yeah. There was a lot of translating things from Haskell to Scala 1:1, and that didn't always work out so well. Well, actually it does mostly work on a technical level, but with heavy costs when it comes to ergonomics. The implicit imports and poor type inference was enough to cause frustration within our team.

That's why I specifically mentioned ZIO. Things improved greatly after migrating to it. It feels like it plays to Scala's strength. It infers well and we don't have a single implicit import to make it work. Well, with the 1 exception of the optional Duration syntax so that we can write "5 seconds" instead of "Duration(5, TimeUnit.SECONDS)".