Check your iPhone storage right now.

Go to Settings > General > iPhone Storage and scroll down.

Look at “System Data” or “Other”.

Is it 30GB, 40GB, 50GB or more?

You have no idea what’s inside Apple doesn’t tell you and there’s no “Delete” button.

However, there’s a trick to clean it up. Here’s how: IMPORTANT BEFORE YOU START: BACK UP YOUR MESSAGES FIRST

Go to:
Settings → Messages → Keep Messages

Change it to "Forever"

If you skip this, your old chats might get deleted during the process.

Done? Now continue.