Below are fascinating Internet niche communities (that aren't reddit) and long-form publications I've come across:
antilibrari.es
thebrowser.com
uncommon.cc
openmasters.org/who
snarkmarket.com
fivebooks.com
hyperlink.academy
blog.longnow.org
thestoa.ca
fo.am
bldgblog.com
flowingdata.com
pudding.cool
subpixel.space
palladiummag.com
youtube.com/channel/UCs7nP…
theschooloflife.com/thebookoflife/
everything2.com
alone with virtual objects on screens.
Dynamicland is a community space, where the people of Oakland will come to “live in the future”.
dynamicland.org/#project
edge.org
plato.stanford.edu/index.html
interintellect.com
progressstudies.school
waitbutwhy.com
moretothat.com
meltingasphalt.com
lesswrong.com
fs.blog/blog/