Encrypted storage.

Not necessary.

It was encrypted to begin with, then you erased it. Without the key, it's lost.

All you would accomplish is using another handful of cycles.

From my understanding, modern phones encrypt the local storage. 
When you factory reset the device, the encryption key is destroyed & the storage is formatted. So even if a forensics lab was able to pull the storage chips, anything left behind would just be hashed data, meaningless without the key.

Hey y'all, I was wondering about something. I know that with SD cards, there's an "Overwrite format" option that allows you to simply overwrite the data on the cards and then format, so that it's harder to retrieve data.

Could you do the same on an Android device like a Samsung S22 by filling it with a nonsense file and then factory resetting it?

How to Securely Factory Reset a Samsung S device