Q.Potted kale lead that was infected by bugs
I have treated the plant . Should I cut off the infected leaves I don’t see any new growth.

Treat the plant with Neem Oil.
Neem Oil is organic and safe for people, pets and bees.
Yes, you can trim the damaged leaves from the plant. Try increasing the sunlight available to your plants.
https://www.gardeningknowhow.com/edible/vegetables/kale/growing-kale-in-pots.htm
https://www.gardeningknowhow.com/edible/vegetables/kale/kale-plant-protection.htm