Scala doesn't have operators (as in, + - * / ++ -- ... are just methods) and at some point library authors went a little overboard with DSLs using symbolic name

Scala doesn't have operators (as in, + - * / ++ -- ... are just methods) and at some point library authors went a little overboard with DSLs using symbolic names, especially for concepts coming directly from Haskell. But those days are mostly over. The type system is very powerful and a few concepts have complex semantics, there's no way around it. But in my experience what really hurt inexperienced developers is the mix and match of Java constructs and more functional or Scala specific ones. And in my opinion, the Kotlin ecosystem is even a bigger offender nowadays, while best practices in Scala have somewhat converged, as a direct consequence of its decline in popularity, i.e. because people have stopped trying to use Scala as a better Java.