In terms of the negativity, I'd say that unlike other cars of similar design (like the Aztek) -- a way higher percentage of the panning I see online is about it not living up to its promised capabilities. There's loads of videos of Cybertrucks needing to be towed out of bad spots by other trucks, problems even when it isn't stuck because of how little its frame flexes, the additional torque wearing away tread on the tires much faster, etc. Some of those things can be engineered around and I'm sure Tesla engineers are working on it.
I'd hazard a guess that the market share the Cybertruck is taking isn't any existing trucks but rather more "luxury-class" SUVs like Mercedes, Land Rover, and BMW.