It's the same deal on FFXIV, though there is generally a higher real player-to-botting player ratio over there.
Not really- you just can't see them because they use hacks to move under the floor/terrain where they can't be seen. This is easily revealed by just turning the recently added chat bubble feature on. Turn it on and go to the Limsa Lominsa aetheryte- if you look down towards the floor you will periodically see talk bubbles from RMT bots spamming chats- this makes it incredibly obvious that they're RMT and yet SE apparently still needs to conduct full investigations before actioning them, at which point they've already deleted and made a new spambot.

You would think the most egregiously obvious bots would be actioned without needing a full investigation as it's obviously not something a legitimate player can even do at all. But nope.