There is a strand of thinking that work = slavery, or at least working for someone else is. I disagree - I think working is a fundamental moral principle. We don’t want to allow a healthy, able-bodied person to live an easy care-free life if all they want to do is sit on the couch.
Begging is a useful activity. It allows the giver of money to feel good about themselves. I would far prefer someone begs for their living, which takes effort, than sitting on the couch and have a check come to them automatically.
We organize our world around people providing useful labor. You can pick whatever labor it is you want that is useful (someone pays for it) but you have to pick something. Money is just a tool for compensating services.
Obviously the world is super complex and edge cases exist all over. But the moral principle is that I don’t want to give healthy, able-bodied people the right to do nothing except what interests them. I don’t want them to write poetry and paint all day unless someone else is willing to pay them for their output. That’s providing a useful service. Otherwise it’s just masturbation.