Google is your friend:
https://benhoyt.com/writings/the-small-web-is-beautiful/
https://ar.al/2020/08/07/what-is-the-small-web/
https://blog.kagi.com/small-web
Another related term: https://en.wikipedia.org/wiki/IndieWeb
see also: https://en.wikipedia.org/wiki/Gemini_(protocol) (NOT web, but similar in spirit - an extended "Gopher"-like protocol)