> And imo they have a largely negative impact on the language: it used to be the case that you could look at a piece of Swift code and roughly understand how it would compile to assembly pretty easily, but with these new features there's a ton of compiler magic going on behind the scenes.

What do you think the ratio between people who want to understand what the assembly will look like, to people who want a simple and powerful way to write apps? I think it's very close to 0.