It doesn't really matter how the chatbot saves the money, they can just see the end results and use the money for bonuses instead.
With customer service systems I have to disagree here. I've got experience working with these issues and for the vast majority of companies most contacts to customer support are for small, banal, things that current crappy chatbots can easily solve. The 80-20 rule works here too.
Bad companies try to do too many things with their chatbots, and use it as a way to make it harder for customers to actually get to talk to a human.
Good companies use them to allow customers to solve common issues faster than getting a real human on the line.
Then there's the other issue of how people want to find information - some people want to find it themselfes and do not want to talk to a person, whereas others specifically want to ask someone and do not want to look at all. For the latter group, no chat bot or fancy autocomplete knwoledgebase (Looking at you Zendesk) or similar will work. They'll always try to contact support as their first step, and they will get very frustrated if you make it impossible.
If your a more software oriented company, it can be very benificial to have software developers (or even a team, if you're a larger company) devoted to helping support. The majority of issues customers contact support for are UI/UX or business process related, and if you systematically start to solve them you will reduce customer support burden and customer support related costs.
I even had a weird thing with Apple a couple of weeks ago. Some edge case related to buying something. The chatbot and telephone tree was as frustrating as anywhere else but once I got to an appropriate person it was trivial to solve.
Yes, and that's the problem: solving 80% of the problems may be a net positive for the company, but it is a net negative for the users: they are now interacting a bunch of time with a device that isn't able to solve their problem, resulting in a negative experience for 20% of the customers. If a waiter would refuse to help 20% of the customers by pretending to take their orders but not actually doing anything with them then that would kill the place where that person worked.
Solutions like these should not work better than 50%, they should work as often as a human on the other end would work, so closer to 100% including escalation options in case it ends up not working after all.
That's not going to serve the company when they deploy it to take orders at a drive-thru. McDonalds pushing the state of the art, now that's interesting!
(from https://www.azlyrics.com/lyrics/peterpaulandmary/paultalk.ht..., c.1960s)
I don't think that if you want to be in business for a long time, aiming to frustrate your customers is a good idea, assuming you don't have some monopoly position.