Duolingo is not worth owning because its core product can be replicated by AI, and the market compresses the multiple before revenue falls once a moat is gone. It has 150 million-plus monthly active users with ingrained daily habits and is integrating AI faster than most, making it more defensible than average software, yet it is still down 80% this year. Software companies with replicable core products are being rerated lower across the board. x.comÂ