> In reality the reasons why JS devs are so focused on the JS code size is > because all the other numbers are harder to obtain. And we need some numbers > in order to fabricate (pseudo) objectivity.
There's a real reason why JS size is important, usually much more important than the performance. In most cases you can tolerate bad performance - because modern PC and even Phones are so insanely fast that it's almost impossible to slow it down unless you do something really stupid or heavy interactions like games, so bad performance is forgiven and nobody cares too much about it. But the latency and bandwidth - are not so fast, and won't forgive you. JS size matters becase it causes direct loss of money. And that loss is visible and very easy to measure. And is usually measured by marketing department. So it is not JS devs who care about JS size. It's the marketing/sales/finance department who cares about it. Sites spend money to attract new users to new site/app, every single millisecond of delay - means user may leave before site is loaded (new users don't know your site and doesn't have good motivation to wait), but you still pay Google for that lost user. Size of images are different story because they don't block user interaction.
