RMT bots don't get deleted when they get permabanned. I know this because the ones I blacklisted that have long since been banned are still on my blacklist, whereas actual players who delete their character or transfer servers will show up as "Unable to retrieve".
I've seen over 100 bots active simultaneously on Cactaur alone when it was at its absolute worst (Via player search) and they've been purging a few thousand gil farming/RMT advertising bots every week for who knows how long, so they definitely do comprise a significant part of the game's population.
