That sounds like 5 humans got replaced by AI. I don't think most people worry about whether all humans will be replaced, simply whether or not they will be replaced, or people they care about.
Which is very short sighted. You or anyone close to you might not be replaced but it should be clear that you don't want to live in a society with 20% unemployment.
Or all 15 people are still employed doing the work of 22.5. Or even more people have been hired now that each person can generate 50% more value than they previously could. Or people are reallocated from the AI assisted task to another. Or some combination thereof.