Well, let's clear up one thing, the airplane won't suddenly go down if you leave your phone on or forget to put set it to airplane mode. Flight attendants simply urge passengers to turn off their electronic devices because they could potentially interfere with the frequencies that are used for air control. This is precisely why it is advised to especially turn it off during take-off and landing.
Even if your aunt is calling you to check if you are okay or you want to watch just one more Tik-Tok video, it can probably wait.