To me, the killer feature of React is how easy it is to mix with standard "vanilla" JS libraries. The "React" version of a library is usually a fairly trivial wrapper around the "normal" version. In contrast, integrating with Angular is a lot more involved and is in effect its own ecosystem.

The other thing I can't stand about Angular is that it puts its proprietary templating language "in control" of components. Which means if you want to do something more complicated that isn't implemented in the templating language, then you just can't (or you end up fighting the framework). With React, it's as if the equivalent of Angular's controllers (components? - it's been a while since I used Angular) were in control. The templating is only for templating.

FWIW, I agree on the ternary operator issue. Although IMO this is actually a deficiency in JavaScript rather than in React/JSX: If if-else and switch in JavaScript were expressions then this problem would disappear completely.