Capitalism is sold by liberalism as a grand system where everyone is on equal footing as buyers and sellers of goods and services, including labor. Consumerism is pushed by capitalists to increase the purchase of commodities beyond what would naturally happen (no need for a new phone every year), a sign of capitalism's inefficiencies.

Earning more through labor isn't wrong, but the problem is that the system is built off of the theft of value created by workers, and parasitic capitalists sitting at the top siphoning off vast amounts of material wealth. Every sale of a commodity continues this vast siphon from the working classes to the capitalist class. UBI doesn't fix this, what would fix it is moving onto socialism, where public ownership is the principle aspect of the economy, the working classes are in control, and production and distribution are aimed at satisfying needs, rather than private profits.