[csswg-drafts] Why argue against features based on performance?

danegraphics has just created a new issue for https://github.com/w3c/csswg-drafts:

== Why argue against features based on performance? ==
I'm not sure if this is the place for this question, but I couldn't think of a better place to ask.

When reading about desired CSS features, I often find that the most common argument against one or another feature suggestion is "performance" (my interpretation of "performance" is the CPU load and/or the render time of running the CSS on a client's computer).

However, I often do not understand the argument of performance because, most of the time, the designer is going to implement the feature regardless, even if it requires javascript to implement. 

When it comes to accomplishing a desired design, the choices for the designer are either a javascript implementation, a CSS implementation, or just not accomplishing the desired design altogether, and most designers, including myself, usually find the latter suggestion to be completely unacceptable (What can I say? We want our dream interface).

In my experience, javascript always has worse performance than native CSS, to the point that the lag of the javascript is actually _visible_ for most javascript implementations of what could be a simple (user-side-wise) and intuitive CSS feature.

So if we're talking about the performance of the website as it loads and runs, then, at least for the simpler more intuitive feature suggestions, a CSS implementation will always be superior in terms of performance. In fact, the reason most designers ask for a pure CSS implementation is FOR the sake of performance. 

For these reasons, I do not understand the arguments against simple and intuitive CSS features due to "performance issues", especially now that computers are getting faster and faster.

So am I misunderstand what is meant by "performance" in these discussions? Or is there an inherent difference in how CSS and javascript run that make javascript more lightweight somehow (despite always being laggier than CSS)? Or perhaps there is something else I am missing?

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_An example would be the idea of a parent selector. Thankfully we're finally getting the :has() pseudo element, but the reason it has been put off for so long was this argument of performance._

Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/2731 using your GitHub account

Received on Friday, 1 June 2018 16:52:46 UTC