Yeah... no. I’d rather keep the physical passport with me. The phone might not work in other countries or its battery might have gone dead at just the wrong time.
Passports never have dead batteries and function in every country.
As for being afraid that a digital passport could be used to track you—your smartphone is already doing that. Your name is also on the plane manifest. Plus, when you use your credit card, your location is sent to the issuing bank and becomes part of your credit card records.
Phone can track you——The biggest reason WHY I do NOT have one.