Comment by blooalien

The problem sadly isn't even mobile-first vs. desktop, but rather designers who still haven't figured out that the web is dynamic content that should be allowed to flow according to the user's display device size and shape. It's not and never has been a static medium like paper. It's not limited to a specific size and shape like paper, and should not be treated as if it were. Web "designers" should not be trying to force the content into any specific size or pixel resolution, as there's just too many different resolutions of screens and width vs. height layouts of those screens to ever be able to cover them all appropriately without adapting to the idea that the content must be able to flow accordingly. It also severely harms accessibility for folks with vision issues who might scale up their fonts to compensate if doing so causes the content to break in horrible ways that make it unreadable.