I also think there is probably a certain chunk of Zoomers who'd answered "NO" to that survey question who fail to equate democracy with democratic socialism or pure socialism. From their perspectives, the latter two are superior options not emblematic of how the American government is presently being run.

They (rightfully) view the current U.S. system of government as a corporate oligarchy. In other words: they don't view our current democracy as living up to the potential of what democracy could and should be, so they answer "NO" rather than "YES" to the question when asked if democracy is superior (using America's current flawed democracy as a baseline for the definition of "democracy" per se).