Yes, it takes some human oversight to fight botters, but that's unfortunately going to be a given for any system that isn't hugely punishing to specifically only the non-botting players. I think most people agree autobans for tripping automatic flags is ridiculous, so there will have to be some kind of oversight anyway.
Botters don't care about captchas, they will never see them, and their scripts can solve them rapidly. :P FR is a perfect example of this-- the captchas stopped the bots for a few months, and then never again. Neither do they care about being permabanned, because most of them aren't playing to play the game-- it's usually a real-money-trading issue at the core, where they are farming up premium currency to exchange for a real life currency at a rate lower than whatever site's own exchange rate is(because it's all raw profit to them), and they aren't particularly concerned about the value of the things they are farming, just that they offload them quickly to an unsuspecting userbase. The only really effective way to fight that is human oversight, unfortunately. There is no automagic cure that isn't more debilitating to the legit players.
Conversely; your players that need accessibility devices will be harshly affected (there are more accessibility cases hindered by captchas than merely needing something spoken aloud), and the only players sitting at the computer screen to see them and be bothered by them are the people playing campaign fairly.
I know oversight is definitely an issue with LW! That sucks! But Captchas belong back in the 90's, when they still barely worked. >:P
Edit: I really do sympathize with people and games that are affected harshly by botting, it genuinely sucks, and it does play havoc on game economies in ways that are harmful. Especially with games that don't have the most active and responsive teams to deal with it. But I'm never gonna support something that trashes the user experience of the people playing legit, when it doesn't even work to deter the problem to begin with. It will stop a couple script kiddies, maybe, but so will the knowledge that someone even has even bare-basic campaign logs to look at.