When you are that poor, you need every hour of work you can get to make rent, buy food etc. You can't take time off to interview for a better job, or to study for a new career. You are stressed from a thousand extra decisions about money that the cushion of a little extra cash could save you. Also you are one emergency or injury or illness away from losing your apartment, or going hungry.
That's why advocates call for a living wage, a wage that people can make enough to live on. If they have the capability to do more, then that gives them a better chance to achieve it.
Though there will still need to be people working retail.
As for how fun it is to interact with people... that definitely depends on who you are and who you are interacting with. If you know someone working retail, ask them how it is.