Why my car wont start without a jumpstart?

I was told the tension pulley was making the belt squeek. The battery is kind of old but the car isn't cutting off by itself how would if I know if it's the alternator

the average battery life is 3-4 years, a old or weak battery can fool the charging system (alternator)

By the belt or one of those pulleys being messed up you think that can drain the battery? Or how serious is the pulleys being messed up

maybe not drain the battery, but definitely not charge correctly , I would not drive a car with bad pulleys