Interesting in this context is completely divorced from morally good/bad. Could be any group from any area at any time in history. I’ll start with a few, followers of the cult of pythagoras, contemporary black Hebrew Israelites, antiracist skinheads and the Amish (neo-luddites in general). Don’t be racist or a prick to other people discussing.
That’s a tad better but absolute extinction seems a smidge extreme when humans can indeed live in symbiosis with nature. I’m guessing a mind that has reached the conclusion extinction is the one and only way is quite unhappy.