A bill reflects the price of the service you were provided and how much of it you used. The DSA can socialize that payment, charging an out-of-pocket price of zero while taxpayers cover the tab. It cannot abolish the underlying cost of providing the service.
Nor can it abolish scarcity. A doctor’s time is limited. Apartments in Manhattan are scarce. Only so much electricity-generating capacity is available at 6 p.m. on a hot day in August. All goods and services require finite resources, whether they’re skilled teachers, construction workers, bus drivers, farmland, or whatever else. This is the central constraint nonmarket systems face when suspending market prices.
https://www.cato.org/blog/dsa-can-abolish-bills-it-cant-abolish-costs