I don't get the point. I get BTC for my Job. Beside the heavy variations about how much 1 BTC is in my currency, how do i buy things with that? Sure, some etail

I don't get the point. I get BTC for my Job. Beside the heavy variations about how much 1 BTC is in my currency, how do i buy things with that? Sure, some etailers like Dell accept it. But if i ask now my local supermarkt how much BTC is needed to pay, i would see in a lot of overwhelmed faces. Same counts for my rent and so on. So what exactly is the benifit of this service? (Maybe i don't get the whole "bitcoin"-Thing anyway)