Apple Store personal data breach

Features like passcode, Touch ID or Face ID helps secure your data by preventing those who don't have your passcode to access the data stored on you device, however, this will also prevent Apple technicians from examining and repairing your device, i.e., system diagnoses and system checks that can make sure everything is working fine.

To prevent your personal data may be compromised, I recommend you to make a backup for you device and erase it before scheduling for a repair.

In case you don't know how to make a backup: How to back up your iPhone, iPad, and iPod touch - Apple Support

In order to completely access the phone, including possibly restoring it to factory state, it needs to have passcodes, FaceID and Apple ID removed. So, yes, it's pretty standard.

The way to avoid any concerns is to erase the phone before taking it to be repaired. Even if the screen is broken, as long as I connects to a network, you should be able to do the through Find My iPhone.

See also:

Get your iPhone, iPad, or iPod touch ready for service - Apple Support

You need to realize that anyone needs to access the device if they are supposed to work on it. When I've taken something in for a repair, I copy my entire drive, wipe it, and install just the basic Mac OS or iOS with an easy password (such as 1 2 3 4 5). They can access everything they need and when I get it back, I restore it from my backup.

I do hope you did a backup because a) the likelihood of your device being erased and the basic OS being reinstalled is high and b) Apple suggests a backup before bringing it in precisely because of that.

Yes, you should be able to trust the Apple repair process - that is not the point. The point is: you really need to take the time to read the terms so you are prepared before you turn in the device. Read the warranty terms here:

Legal - iOS Warranty Document Us - Apple

and make a note of this section:

YOUR RESPONSIBILITIES

YOU SHOULD MAKE PERIODIC BACKUP COPIES OF THE INFORMATION CONTAINED ON THE APPLE PRODUCT STORAGE MEDIA TO PROTECT THE CONTENTS AND AS A PRECAUTION AGAINST POSSIBLE OPERATIONAL FAILURES.

Before receiving warranty service, Apple or its agents may require that you furnish proof of purchase details, respond to questions designed to assist with diagnosing potential issues and follow Apple's procedures for obtaining warranty service. Before submitting your Apple Product for warranty service you should maintain a separate backup copy of the contents of its storage media, remove all personal information that you want to protect and disable all security passwords.

DURING WARRANTY SERVICE THE CONTENTS OF THE STORAGE MEDIA WILL BE DELETED AND

REFORMATTED. APPLE AND ITS AGENTS ARE NOT RESPONSIBLE FOR ANY LOSS OF

SOFTWARE PROGRAMS, DATA OR OTHER INFORMATION CONTAINED ON THE STORAGE

MEDIA OR ANY OTHER PART OF THE APPLE PRODUCT SERVICED.

So, Apple tells you to remove all personal information; their techs are not to blame because they need access to the device - sorry. They cannot work on it if they do not have access.