Heh, the N64 was the first game console I ever used. I thought it was pretty spiffy. I still think it's pretty spiffy. In fact, looking at some screenshots, I would totally play some of those games over ones we have now.
Ignoring that, I agree with your point wholeheartedly: just because things work now does not mean we can't optimize. In fact, a very large part of the software field is all about optimizing things that already exist.