As I understand, there is essentially no difference between these two distros except for the fact that Debian strips down certain non-free firmware, codecs, etc. or whatever to become more "FOSS friendly", whereas the `buntus don't do the same. Debian is also reputed for sporting old (ancient?) packages that may be buggy, and their UI has some crappy defaults (like no font-aliasing on XFCE).

So, as a home/laptop user, what is a specific benefit I get using debian? As per my understanding, unless you own one of those rarely used CPU architectures (like MIPS, PowerPC, SPARC, etc.), there is no good reason for installing debian instead of ubuntu, please correct me if I'm wrong?