Whenever you ask a question like this, please remember Einstein's
Equivalence Principle - at least locally, UA will be indistinguishable from the gravitational model proposed by RET. This is a direct consequence of RET, not FET. Whenever you think you've found a difference that can be locally demonstrated, you're either misunderstanding the physics behind RET (a likely scenario), or you're disproving it (which would be exciting!).
Your confusion stems from a misunderstanding of frames of reference. The Earth, and the air immediately above it, are both accelerating upwards with regard to a hypothetical observer external to UA. As the air accelerates upward, it pushes the piece of paper up, causing the force you're interpreting as air resistance.
This scenario can be easily reframed into a local observer's frame of reference, one that's stationary with regard to the Earth. From that FoR, the Earth and air above it are stationary (by definition), and the piece of paper is affected by a gravitational pseudoforce and drag.