It's somewhat alive. I still run a BBS and am the NC (net coordinator) for Wisconsin/Minnesota/North and South Dakota. (an area that used to be considered a "Region" back around the turn of the millennium). My FidoNet address is: 1:154/30 (and also 1:154/0)
There are 9 FidoNet nodes in my net. (154) I added 2 new ones within the last month or so.
My BBS is accessible at: https://warensemble.com It can also be accessed via SSH, Telnet, and possibly dialup but the program that handles my modem often checks out on me without warning (usually after a dropped call, which happens far too often over a VOIP line)
The joke is that Fidonet will eventually just be 2 sysops sending netmail back and forth to each other, where they argue about the policies and methods of how that mail is sent.
A lot of current BBSes may have archives from the last 10 years or so. I know mine does: https://warensemble.com