I can’t delete any apps from my iPhone 7

I am assuming that you have iOS version 14 installed on your iPhone 7.

You may have Screen Time Restrictions set to ON.

Open Settings ➔ Screen Time ➔ Content & Privacy Restrictions ➔ iTunes & App Store Purchases ➔ Deleting Apps : Set this to ALLOW.

Axel F.

Please check: Settings - Screen Time - Content & Privacy Restrictions - iTunes & App Store Purchases - Deleting Apps = Allow. 

You are quite welcome.