To make a 22 nF capacitor using a pair of copper pours separated by a 1.6 mm thick old school two-layer PCB, we would need something like 10 square feet! It would have to be an electronics art project, intended to be displayed on a gallery wall. :)
That goes down to something like 90 square inches if the separation is a 0.1mm thick layer of a thin four-layer PCB: still an impractically huge area.
Capacitors achieve their density in a small package by two tricks: extremely tiny dielectric gaps, and convoluted surface areas.
For instance, electrolytic caps achieve a big surface area due to using rough, anodized aluminum (or tantalum) for the anode (mnemonic: anodized aluminum -> anode). Then every ridge and crevice in that anode is available for capacitance due to using an electrolytic gel for the cathode. The roughness of the anode and the gel optimize for high surface area. Then the thinness of the oxide layer optimizes for a small gap size, also favoring high capacitance.