I use a stethoscope to listen for airflow in the lungs and murmurs of the heart. In both cases I would still order more imaging before finalizing a treatment plan unless it is for something emergent. Ultrasound cannot assess airflow well so I don't see it replacing the stethoscope in that regard.

My unpopular opinion is that point of care ultrasound is a fad and will eventually be phased out of physician workflows. This is because I haven't seen it actually change someone's medical decision making. More often, people use it as a means to justify why they haven't actually made a treatment decision yet.

The only way I could see it have adoption is if actual radiologists (which as of now are the only physicians that went through standardized examination confirming competency in reading ultrasound studies) started doing rounds in the ER and on the wards.