You guys are totally spoilt!
It's pretty obvious that you've never had to work with 1MB RAM, 60MB HDD, 14.4kb modems and paying a fortune per minute to the phone company!!
Back then every byte counted, jpegs were squeezed as much as possible and 640x480 was considered a huge image!

Even today we need to do some planning ahead, and not just pour more images/pages at poor Xara (and the net) until it kneels.
Everything needs to be split when growing too big - books, libraries, movies, museums etc, and when working with big web sites (aka library!) there is absolutely no need to work on all the pages at the same time. It's often easier to plan this from the start than trying to split it later.
Xara has made it so easy to make great web sites that it has made its users spoilt that they forget simple things like editing one (or a few) page(s) at a a time.