Pixel video looks warped when I zoom in to 2x or 3x

That wobble is the lens hand-off plus stabilisation catching up. Photos don't show it because a still just picks one lens. Two things help: set the zoom before you hit record rather than pinching during the clip, and in the video settings switch stabilisation to Locked or Standard instead of Active, which leans harder on digital correction. Also try it in better light. In dim rooms the phone crops in more for stabilisation and straight lines bend for a moment at the switch point.