How would those other technologies deal with the situation where grandma signs into her banking account via app on her phone and then gets distracted, leaving h

How would those other technologies deal with the situation where grandma signs into her banking account via app on her phone and then gets distracted, leaving her phone unlocked on the table for teenage Jimmy to find? My bank uses short sessions so I get signed out within a few minutes of inactivity. Long sessions would seem to leave grandma wide open to this sort of local attack.