[virtualwhys]

What about non-frustrated Scala users, should they drop Scala and Scala.js in favor of an effectively experimental language with zero industry adoption?

Post-Scala is already under way with the new compiler, Dotty[1], which will replace present day Scala.

[1] https://github.com/lampepfl/dotty

[paulddraper]

Non-frustrated Scala user here. I recommend you not switch in that case.

You'll have to admit though: the greatest strength and weakness of Scala is Java.