Why can for..of + push () be faster than Array.from (foo) and [... foo]?

Question

I often use Array.from()or [...foo]to get an array of iterable objects. I can also repeat it and click on the array manually instead, but I would prefer the native one, because it was very simple, and I thought that its implementation would be more efficient.

However, I found some test result that shows that that native path is slower .

https://jsperf.com/set-iterator-vs-foreach/4

I also ran tests with fewer (50) or more (10 thousand) elements in Chrome and Firefox, but I got a similar result.

https://jsfiddle.net/unarist/k0cu8wta/2/

I understand that it’s [...foo]faster than Array.from()because I Array.from()have to process objects like array and parameter mapFn, but I could not find a plausible reason between [...foo]and for..of+ push().

What makes for..of+ push()faster than Array.from()u [...foo]?

Update: My concern is not how fast and what should I use. I was surprised that the native version is slower than the JS version, and I wanted to know why, because I thought "in general, the native is fast."

(for example, a native has more work than a loop + push path, special optimization for something, etc.)

I tested Chrome 60 and Firefox 54 on Windows 10 x64.