yeah but you're dismissing the fact that this was just a pregen table of data back then. They made a map based on that, sure, but from that table came... everything else and you can't store all that data on floppy.

Similar techniques apply today. Pregen like 100,000 stars. Give them names and locations in the galaxy, treat them as your "locations of interest" with a seed. The rest can just be another cloud of particles with no interest and if the player visits, you can RNG whatever based on the seed. No two systems can share a seed. They can, however, share a branch.