> I wish that all of those projects, tutorials etc. that explain how to write their image to a block device, like an sdcard, would start advise using cat, because there is no reason to use dd, it's just something that people stick with because others do it too.

I'd wondered whether dd or cat were faster, and indeed cat is faster, but not by much. Also, for some embedded devices, you have to write to specific offsets, so dd is more convenient and explicit. Lastly, cat composes poorly with sudo.

  $ sudo dd if=foobar.img of=/dev/sdi # works
  $ sudo cat foobar.img > /dev/sdi    # fails unless root b/c redirection is done by shell

> I only use dd for specific blocks, like writing back a backup of the mbr, or as a rudimentary hex editor.

xxd / xxd -r is much nicer, but I suppose sometimes vim is not available...