It's all about the batteries. I think someday we'll look back and marvel at how large our original MS batteries were and how little energy they held.
Kind of like my 428MB 3.5" HDD I use as a paper weight on my desk. It was WAY more storage than I would ever need.
I have older and less dense computer stuff but the size is printed on it so large and prominently. And it was the first piece of hardware I thought would last (at least the space would last) for decades.