Why does dynamic power dominate at higher technology nodes

The main reason dynamic power dominates in higher technology nodes is because transistors switch much faster, and there are many more of them packed into a chip. Dynamic power is the power consumed when charging and discharging the capacitances of the circuit every time a signal toggles. Since frequency is higher in advanced nodes, signals switch more often, and that increases the dynamic power. For example, in a modern processor running at GHz speed, the switching activity is huge compared to older designs.

dynamic power dominates because supply voltage does not scale down as much as the transistor size. Ideally, if voltage went down a lot, power would reduce, but in practice, we cannot reduce it too much because of noise margins and stability. For instance, in a 7nm chip running at high clock speed, dynamic power in switching logic often outweighs leakage by a big margin.