Except that, it's starting to
not work. It's only a matter of time before current software will stop working on Windows XP.
Also, being insecure and unpatched, in my book, absolutely counts as "not working," particularly when hackers have a very real interest in finding those vulnerabilities and gaining at the expense of those users still using that OS for their daily computing.
While I can totally understand that there are edge cases and specific reasons why some people might want to hang on to using an older OS for a while, 12+ years is really starting to stretch it.
And actually, Office 2003 is kind of poster child for why people
should upgrade, at least to Office 2007. In addition to 2003 having its own software vulnerabilities, it uses legacy office file formats. The rest of the world is moving to the
Open Office XML specification, which was introduced in Office 2007. I'd be very surprised if within the past 7 years, you haven't received at least a few office documents you've had trouble opening.
Yes they are, and you
don't need XP to run them.