A symbol is a symbol. A flat monochrome floppy disk icon represents the concept of saving a file just the same as a lovingly rendered 3D floppy disk or even a photograph would.
Text glyphs are very flat, abstract symbols that represent sounds or ideas (indeed, I'm pretty sure the whole "flat design" trend was inspired by typography in the first place). Sure, we've been hunting beasts for much longer than we've been reading and writing, but written language is still a very old invention in the human timescale. And art predates even that. Humanity has had plenty of experience with symbolic visuals over the ages, I think we're equipped well enough to use basic smartphone apps.
Text glyphs are very flat, abstract symbols that represent sounds or ideas (indeed, I'm pretty sure the whole "flat design" trend was inspired by typography in the first place). Sure, we've been hunting beasts for much longer than we've been reading and writing, but written language is still a very old invention in the human timescale. And art predates even that. Humanity has had plenty of experience with symbolic visuals over the ages, I think we're equipped well enough to use basic smartphone apps.