I will lose a beautiful API with a simple, terse and familiar syntax. I will have to work with an ugly, inconsistent and loquacious API, which has no guarantee of being cross-browser (or accounting for various browser quirks).
And for what? I doubt 81 KB would make much difference to 99.9% of my visitors.
As for performance -- it makes sense to rewrite bottlenecks in pure highly-optimized JS. But to write vanilla JS from scratch, without even knowing whether you'd need that performance boost is a pure waste of time.
UPD: it has been pointed out that this webpage is directed at developers of JS libraries. In this case, all these points are valid, but the title, then, seems to be either misleading (as in "link-bait" misleading) or a plain truism.
You lose dependency on a monolithic library which creates vertically-stacking dependencies and library conflicts. By ditching it, you gain the ability to construct your app out of loosely-bound components supported by independent developers.
Obviously, you cannot have dependency conflicts if you only have a single dependency! We need a slightly more complicated example to understand the problem. Let's say I'm making the new customer checkout page for my startup.
I decide to call an e-mail address verification as a service API, their library uses jquery 1.8
I decide to call an address verification as a service API, their library uses jquery 1.11
I decide to call a credit card validation as a service API, their library uses jquery 2.0
You go to the e-mail address verification company and say "Do you have a version that supports a newer version of jquery" and they say "yes, also we redesigned our library's interface so if you upgrade you'll have to change all your code..."
I will lose a beautiful API with a simple, terse and familiar syntax. I will have to work with an ugly, inconsistent and loquacious API, which has no guarantee of being cross-browser (or accounting for various browser quirks).
And for what? I doubt 81 KB would make much difference to 99.9% of my visitors.
As for performance -- it makes sense to rewrite bottlenecks in pure highly-optimized JS. But to write vanilla JS from scratch, without even knowing whether you'd need that performance boost is a pure waste of time.
UPD: it has been pointed out that this webpage is directed at developers of JS libraries. In this case, all these points are valid, but the title, then, seems to be either misleading (as in "link-bait" misleading) or a plain truism.