It didn't require any coding skills, and you could make a little page and suddenly be on the Internet. Back then, search engines were very basic, so there was this common idea of needing to have your domain, your site (both words being used traditionally to describe land and property), so you'd have presence. A more recent analog Myspace, where people could have a profile, show off what they liked, these kinds of things.
Fun fact: the entire Geocities archive was saved by a bunch of fans (I saw them at DWeb Camp this summer) and is below 500Gb - so it can fit on an SD card!
There's also a fan effort to recreate the experience of Geocities, called Neocities. It has a bunch of fan pages that will give you an idea of what Geoticies was like.
TBH I miss this era of the Internet when pages loaded fast even on slow computers (although Netscape was very fussy about its HTML). The past 20+ years of "progress" have just seen more and more JavaScript and unnecessary bloat loaded for pages, with very little content on them. Giant fonts, lots of fading-in of content, lots of scrolling required. It's pretty poor!