Totally guesswork here, but I'd say Chrome has a lot more telemetry, profiling and tracking built-in and its users tend to use a lot more plugins, including things like ad-blockers that scan over each webpage and can be beneficial (battery-wise) or not depending on content. Safari users are more of a barefoot type. A power user is more likely to not be running Safari. And a power user may, well, prefer to sacrifice battery power to get the power they seek.
Besides, there's some precedent set in 1998 by a certain OS that "favored" their embedded browser over the competition, so I doubt Apple would want to tickle that fancy.
If I had to guess, it's that Apple refuses to implement very CPU-heavy JS features they don't think add much value in Safari.
I recall some feature I was using that ran in an inferior way to save power on Safari, so much so that I had to kill that feature and use a different API
I think it's more that Apple implements power saving behavior into the JS engine on desktop much like they do on mobile. For example, pausing background scripts on inactive tabs and disallowing autoplay on videos even on desktop.
I would be at least slightly surprised if Apple would deliberately hold back power-saving techniques from third party developers. It’s not like this is something that makes Safari much more appealing to users. Most users wouldn’t even notice that their choice to use Safari is responsible for their great battery life.
I absolutely think there is a conspiracy (inasmuch as "conspiracy" can be defined as "not going out of their way to change it") to make the competitors to Apple applications look worse than their own offerings. It does not reflect poorly on Apple when Firefox performs worse and uses more memory and battery than Safari.
How is Apple suppose to change Firefox and Chrome’s source code?
If either browser’s manufacturer wants to see what Apple does to make Safari more battery efficient, they are free to look at the source code to WebKit.
And as the other person told you already, Safari.app is not what you get if you build the WebKit source. In much the same way that you can't judge Chrome by Chromium, one is the base of the other, not the whole.
It's not impossible, but I doubt it, if only because very few third party applications use as much as Chrome does. The only exceptions are things that actively use a lot of CPU, like compilers or compressors.
Its been a really long time but safari on Windows was a thing and it did run a lot leaner in the background than anything else available at the time (except Opera if memory serves).
It’s entirely possible that Safari is intentionally avoiding features that make it wake up-
I doubt that it does anything unavailable to other browsers, thats MS territory, because they wanted features. I feel like safari, by contrast, doesn't want to add features.
Entirely serious question. Apple is known to severely privilege their own applications over competitors.