Unable download certain apps
I have upgraded my iPhone from 10 to 13 pro recently. After updating I am unable use google assistant, google home, google crome cast etc. The Apps are not appearing in the apps store as well
The iPhone 13 comes with iOS 15. Apparently "Google Assistant" is not supported by iOS 15 (or vice versa). You will have to ask Google why:
How to contact an app developer - Apple Support