We all trust our local bartender, they are the wise host of that party. They need to set that person up for a good evening with a hangover supplement. One priority is giving them the drink they desire. Sometimes people just want to drink in silence and let their mind wander. Other times they just want someone to listen to them. Maybe they just are bored and want to meet new people, or they are celebrating something. A good bartender tries to deliver whatever the guest may need for a good experience.
Someone could make a device that could make drinks, but that’s never going to replace a bartender. A bartender is a friend that goes past just serving you a drink. A bartender is someone a customer enjoys seeing or in the first meeting makes a positive impression on someone’s day. People drink when they are happy and when they are sad; the bartender is there for both of them.