[lptk]

Worth noting that the presenter of this talk has done a complete 180 on subtyping as he's now using subtyping and variance in the core of his flagship library ZIO. He realized it was sometimes better to use the language's strengths rather than denigrate them for "ideological" reasons.

Also worth noting that Scala is not a "very big" language in any sense that I know of. It has a lot fewer features than C#, for instance. And probably a comparable amount to TypeScript.