To criticise Rust for being a complex language misses the point: it's designed to be expressive, which means having a lot of features, and in many situations that's what you want from a programming language.

the piano, as always, has to compete with the guitar

We focus so much on black magic and avoiding it that we rarely have a chance to enjoy any of the benefits. When used responsibly and when necessary, it gives a lot of power and expressiveness.

Without elegant ways of expressing loops/iterators (like angular does with directives), the primary way to keep JSX readable thus becomes copying and pasting.

express one's model of Existence

I think this is being rejected on grounds that are too arbitrary, and detract from what to me are the best things about Svelte -- it's fun and easy to use, and lets you write components in a way that's natural and expressive.