Fixed size layout runs into problems where you're working with displays that aren't at typical desktop / laptop / mobile distances from the retina.
The two obvious examples which come to mind are mounted displays (from wall art and signage to billboards), and glasses-based displays.
A 1cm font size on a mobile device is ludicrously large. On outdoor signage it's invisible, and quite possibly below pixel size. It might be appropriate on a desktop display for some major title or site branding. It's going to fill the entire field of view on a face-mounted display.
The simple truth is that design has to respect not only device capabilities (your colour-palette likely works poorly on monochrome e-ink devices, ask me how I know), and reader capabilities (colourblind? glaucoma? cateracts? presbyopia?, macular degeneration?) but also the specific use case and environment, all in ways that the author of a site or design often has no possible insight on. Client specifies design is the only option which works in all of these instances, and yes, this means that the more complex your site / SPA (o hai ubrz) the more likely it will be to break irreparably in a large number of instances.
The two obvious examples which come to mind are mounted displays (from wall art and signage to billboards), and glasses-based displays.
A 1cm font size on a mobile device is ludicrously large. On outdoor signage it's invisible, and quite possibly below pixel size. It might be appropriate on a desktop display for some major title or site branding. It's going to fill the entire field of view on a face-mounted display.
The simple truth is that design has to respect not only device capabilities (your colour-palette likely works poorly on monochrome e-ink devices, ask me how I know), and reader capabilities (colourblind? glaucoma? cateracts? presbyopia?, macular degeneration?) but also the specific use case and environment, all in ways that the author of a site or design often has no possible insight on. Client specifies design is the only option which works in all of these instances, and yes, this means that the more complex your site / SPA (o hai ubrz) the more likely it will be to break irreparably in a large number of instances.