Unsurprisingly, I completely and utterly agree with Ethan’s assessment here:
I’ve written some code that’s saying, “Once the screen is this size and the element appears in a different, smaller container, use a narrower layout on this element.”
But, well, that’s weird. Why can’t we apply styles based on the space available to the module we’re designing, rather than looking at the shape of the viewport?
I also share his frustration with the “math is hard; let’s go shopping” response from browser vendors:
There’s an incredible clamor for container queries, with folks from every corner of the responsive community asking for something that solves this problem. So personally, I’d love to see at least one browser vendor partner with the RICG, and get properly fired up about this.
We had to drag browser makers kicking and screaming to responsive images (to this day, Hixie maintains it’s not a problem that needs solving) and I suspect even more activism is going to be needed to get them to tackle container queries.