Fundementally, this question is about equity, equality, or Justice.
Now I would like to look at this issue from the perview of human rights. UNHCR has defined 30 basic human rights. These rights include things like right to education, rights to food and water, rights to social services, rights to a free life, rights to shelter. But hypocritically, capitalist policies and privatization of comodities has created a world where one must pay to gain access to what we define as basic human rights. Data shows that 10% of the global population lives under the poverty line. similarly, nearly 18% of the world population lives under a multidimentional poverty without adequate access to proper healthcare, education, etc. In a world where universal basic income exists, millions, if not billions of people would not have the need to starve every 5 days, and dumpster dive for food. They wouldnt have to hide under bridges in the cold fridgid night. They wouldnt have to fight teeth and bone to get quality education. And they certainly would not have to sacrifice their health because good healthcare requires them to take a loan with interests steeper than the slopes of mount everest.
Furthermore, in a capitalist world without universal basic income, there is no limit to which workers can be underpaid. If one looks at supply and demand then one can see how an excess of workers creates a high demand for work. We see again and again in the form of sweat shops in underdeveloped countries how companies use the competetive job market to push wages lower and lower, severely undervalueing the world. In a world with universal basic income, we have a system where regardless of how low prices are driven down, people still earn enough to fulfill their basic needs, and companies are forced to ensure they are able to meet their needs.