Answering calls
Unable to take calls without AirPods does not even allow to put on speakerphone
iPhone 7, iOS 14
Have you tried to Force ReStart your iPhone 7 to see whether that resolves the issue? If that does not resolve the issue then have your iPhone examined at the Apple Store or at an Authorized Service Center for further diagnosis and resolution.
Force restart iPhone 7
Press and hold both the volume down button and the Sleep/Wake button at the same time. When the Apple logo appears, release both buttons. (DO NOT release Side Button when invited to Slide Power OFF).
Axel F.