Black and unresponsive screen. How do I recover the data?

Hey all!

My coworker was working laying down with his iPhone 8 Plus in his pocket which seems to somehow have killed the screen and digitizer, everything else seems to be working. He doesn’t have any backups of his phone so now I’m trying to recover his data for him. The only response I get from the phone is from the taptic engine. He said first the screen went grey so he restarted the phone and since then the screen has been black.

First I thought the screen connectors had disconnected or misaligned so I opened the phone and checked all connections, everything was intact. Then I tried connecting it to my mac but I need to trust the mac before I can access anything. Someone on the internet connected a usb keyboard to the phone and entered the passcode that way, turned on VoiceOver using Siri and then he could operate the phone using the keyboard. The problem is since iOS 11 you also need to unlock the phone before using usb accessories. My mac can only recognize the phone if it’s in recovery mode but I can’t recover any data that way. Now I’m out of ideas, I don’t know how I can somehow backup the phone in this state. I’m afraid the logic board is damaged, not the screen so I think replacing the screen won’t fix the issue but I’m not sure.

One would think there is a way to recover data from iPhones with unresponsive displays but how?