1mb 1999 memory card just stored save files... save files today are also pretty small. I think I've seen some saves today that are like 20mb. Im sure some are bigger, but even 100mb save is whatever these days.
This should have just shown a disc or cartridge that would represent 650mb for disc, and an N64 game could hold 64mb to compare it to today's 150gb games.
I still don't get the big deal. The resolution back then was 480 so textures took up nothing. Today, we have huge games with a crazy amount of unique assets all made for 4k resolution. Somethings gotta give!