No they are not. Even the bigger players like Samsung and Sony have dozens of quality levels of panels. The highest quality ones e.g. have a ton of local dimming zones and smart backlighting, and achieve much higher contrast ratios than cheaper models. They also will represent moving objects with high contrast better. Plus, there's usually different levels of color calibration applied.

That means usually in order to get the best imagine quality you also have to buy the model with the most smart features at a higher price point - even if you don't intend to use them.