My wife has an intel macbook circa 2018? It gets uncomfortably hot just watching youtube videos, my M1 macbook air has never even gotten warm. Her battery life

My wife has an intel macbook circa 2018? It gets uncomfortably hot just watching youtube videos, my M1 macbook air has never even gotten warm. Her battery life seems terrible, maybe it is 4-5 hours or so, but I go days without charging mine with casual use. If you are not diligent about recharging every night, the drastic increase of battery life makes a big difference.