iPhone 7 unavailable after incorrect passcode, how to unlock without data loss?

If your iPhone is telling you that it is Unavailable – and is not telling you that you can "try again in XXXX" – any data that exists only on that phone is gone, or as good as gone. The only way to get back into the phone is to reset and erase it.

If you forgot your iPhone, iPad, or Apple Vision Pro passcode, reset your device without a computer - Apple Support

Hopefully you were safeguarding your "precious photos and memories" by means like

• Using iCloud Photos, or
• Making backups of your iPhone that included photos to iCloud, a Mac, or a PC (if iCloud Photos was disabled), or
• Periodically importing photos from your iPhone to a computer

Then you would have copies of those photos elsewhere - and could, say, resynchronize the erased phone to iCloud Photos, or restore a backup.

Your data is not lost if you have a backup either on iCloud or iTunes.

If you see an iPhone or iPad unavailable message or a "Security Lockout" screen

If you forgot your passcode, you can use your Apple ID and password to erase and reset your device without a computer.

Learn what to do if you see "[Device] unavailable" or "Security Lockout" on your iPhone or iPad.)

iPhone is disabled.

Following this process is the only way out if your iPhone is disabled. The steps given in this link will help you reset the passcode -> If you forgot the passcode for your iPhone, iPad, or iPod touch, or your ...

Regarding your data…

1. If you have an iCloud or iTunes latest backup, then there is nothing to worry about. If not read more...
2. You have synced your data to iCloud, then what you will get back is what you have synced to iCloud and uploaded to iCloud Drive; the information that is synced and stored in iCloud are, Contacts, Calendars, Bookmarks, Mail, Notes, Voice Memos, shared photos, iCloud Photos*, Health data, call history, and files you store in iCloud Drive. (*-If you have turned on iCloud Photos, your content is automatically stored in iCloud.)
3. You have imported your Photos and videos to Mac/PC then they are safely residing there on Mac/PC
4. You have uploaded some of it to Cloud Drives using the Files app (iCloud Drive, Google Drive, OneDrive, DropBox, Flickr, box, AmazonDrive, Adobe Creative Cloud, etc). The data remains there.
5. If you have not backed up or do not have the latest backup, nor imported nor you have synced or uploaded your data to cloud drives prior to the situation that you are in, then I am sorry, all your data is lost.