This example was literally taken directly from real-world code in the React codebase (a script to call jest-cli). While you're correct that there are probably a lot of clearer and more readable ways to write this snippet, the fact of the matter remains that people write code exactly like these "real world examples" all of the time.
Only now?
I was an early adopter of the original decorators proposal as well as the F#-style pipeline operators. The more time has moved on and other bits made it into JS proper, I'm far more inclined to stick to what's "in the box"... Have even considered just writing straight JS + ESM (modules). Of course, I also like JSX, though not sure of any proposals of how to get that "in the box" as e4x died on the vine and a lot of other efforts didn't gain much traction either.
Examples?
If the motivation behind these features are React components, javascript clearly lacks proper logic in array (and object) literals, like
'[' if (cond) […]expr1 [else […]expr2] ']'
[cond ? expr1 : expr2]
[(() => {/*code*/})()]
It makes me really question the judgement of the people that are working on this language, and it explains how some of the shittier proposals manage to slip in and why the good ones are misused all over the place in every real world codebase when this is the kind of guidance devs have on where to use fancy new features.
In a few years everyone is going to collectively lose their fucking mind once again and decide that ternaries are now the devil and every React component should be chock full of do expressions. I can see that coming clear as day. That might finally be enough to get me to throw in the towel if the also incoming decorator hell doesn't do it.