Why is it sometimes that water on the upper floors of a building does not flow through the taps of the water

Why is it sometimes that water on the upper floors of a building does not flow through the taps of the water supply network, while it continues to flow out of the taps on the lower floors?

The fluid pressure is determined by the formula p = ρ * g * h where p is the pressure, ρ is the density,
g-acceleration due to gravity, h-depth.
It can be seen from the formula that the higher the height of the building, the more pressure must be created at its base, therefore the lack of water on the upper floors is due to insufficient pressure.