I knew that the decentralized structure of Usenet was born from necessity, but I didn't realize how hard it was just to get a modem back then.

Can decentralized services work on the modern Internet? Even setting aside how spam and illegal content destroyed Usenet as a discussion medium, in its late stages it became a playground for kooks and trolls at the expense of legitimate posting. Killfiles didn't work as the bad actors could easily change names and email addresses; get them thrown off one server and they'd just sign up on another one. The only way to ban someone from a newsgroup and make it stick is with a court order - and that happened at least once.

Another post from the same blog details why the troll problem was technologically impossible to solve: https://www.cs.columbia.edu/~smb/blog/2018-02/2018-02-23.htm...