Duolingo are not the only ones, I am aware of a project where the whole translation team for internal trainings was replaced by AI automatic translation of training materials.
Any developer that celebrates AI vibe coding, is going to get some bad vides in the coming years.
Wages have lost their relationship with productivity for some time, and while the gains will be privatized, the costs (energy grid, Data center land use, and the carbon emissions) will be born by us all.
So don't think my hostile opinion towards developers that are involved in using AI to abuse their fellow humans is going to be remotely rare in the future. All the necessary preconditions are already there and the only reason it hasn't been noticed yet is because the people that fucked up are still able to get jobs at companies riding AI funding to do AI work.
Look what happened to a lot of the crypto bros. Now multiply that by 10 and the amount of nasty shit they were doing to other workers by 10 and I don't think people are going to take it as lightly as a lot of the crypto bros got off, which was usually just a black mark and severe down leveling when they came back to work at actual companies.