I found FallenSMP and it is a 1.21.11 Java survival server that lets cracked players join too.
The server is up 24 7 and the owner says an alt keeps it running so it should not shut down in the middle of a big fight.
There are basically no rules except no hacking. It is mostly vanilla with voice chat and a few other plugins.
The main thing is the seasons system. Each season the first person to kill everyone at least once then kill the Ender Dragon and get the egg gets a prize. They can pick items with limits on enchants or they can take a 5 minute head start next season.
