It sounds like his FTP is just <100 watts although I wouldn’t discount all the off-bike work that he is doing. A daily 5k in a hilly area with his body weight is a significant effort in its own right. I think the cross-training will ultimately be a good thing for him.

Hopefully, he appreciates how well he is doing. I could see him being discouraged by the short 20-30 minute rides, 🤮, etc. but he has done some great, hard work and is clearly making progress. He should feel some accomplishment, even if he ultimately wants to accomplish a lot more.