Happened to me, too. I could not reset it, because when you press volume and off button, it asks you to swipe, which you can't do. So I force restarted: "Press and quickly release the volume up button, press and quickly release the volume down button, then press and hold the side button. When the Apple logo appears, release the button." More about force restarting: https://support.apple.com/guide/iphone/force-restart-iphone-iph8903c3ee6/ios
It did a force restart, but, alas, the touchscreen was still broken.
If you need to send it in for repair, you still can remote wipe it via the FindMy iCloud function.