> why is [file size] a factor so important it must be emphasized this much?
Because there is no dead code removal. All of it goes over the wire. Even the stuff you don't use.
If you use a 70kB library, you'll pay 70kB in page weight for it. Even if you only use half of it.
The Closure Compiler can remove unused code if its "advanced mode" is used. However, it requires everything to be annotated and to be written in a particular style. Very few libraries meet these requirements.
Those micro libraries and micro frameworks try to address this issue by doing only one specific thing.
[Personally, I prefer something Dart's built-in dead code removal. I really don't want to think about that stuff. Let me put 30 tween functions into one lib and simply don't ship those functions I'm not using.]
Because there is no dead code removal. All of it goes over the wire. Even the stuff you don't use.
If you use a 70kB library, you'll pay 70kB in page weight for it. Even if you only use half of it.
The Closure Compiler can remove unused code if its "advanced mode" is used. However, it requires everything to be annotated and to be written in a particular style. Very few libraries meet these requirements.
Those micro libraries and micro frameworks try to address this issue by doing only one specific thing.
[Personally, I prefer something Dart's built-in dead code removal. I really don't want to think about that stuff. Let me put 30 tween functions into one lib and simply don't ship those functions I'm not using.]