I found some more examples of little electronic tidal pools, where small websites existed in isolation while their contemporaries evolved into vastly more sophisticated variations. Previous examples.
WestNet was a ISP (that's Internet Service Provider for some of you) in New York in the 1990's. Their website was supposedly updated until 2013, but it still reflects a distinctly late-90s design. They still had a page of their users' locally-stored websites. It's really kind of charming.
Welcome to Pinball Expo 1994 is intriguing because its simplicity suggests a site formatted for modern mobile users, who are in some ways the 56k modem dial-ups of the moment (although both enlarging screens and increasing speeds make this less true with each year). It suggests that new innovations will somehow evoke older ones, as early-adopters are forced to adapt to common constraints.