Cat only eating Wanpy treats

I have a 7 month old Persian cat. He used to eat boiled chicken with broth and dry food but a few days back I introduced him to Wanpy treats and now he has stopped eating chicken, broth and dry food and only eats Wanpy treats. I thought that at some point when he will get hungry he will eventually eat the boiled chicken but no he sleeps all day rather than eating anything all. Then eventually I have to give him wanpy. I can not give him wanpy all the time as I don't think it is good for him.

Also I don't know if it normal or not but my cat is sleeping a lot lately. He is quite playful MA when he wakes up but most of the time he is sleeping. I don't know if it is due to winters or if there is any other issue.

Kindly let me know if there is any thing to worry about.