This is not true anymore. At leading edge process nodes (i.e., smaller conductor pitch), the bulk resistivity of copper changes dramatically because it is increasingly dominated by ballistic electron scattering on the interfaces and grain boundaries: surface area has decreased as a fraction of volume and the average grain size has shrunk to fit inside the interconnect lines.
Alternative metals like Cobalt and Ruthenium have been proposed and to some extent used in production as an alternative to Cu for the low interconnect layers, but they just arrest the trend -- the fact is that the interconnect resistance is much higher than it used to be.
It's also why a lot of the big players like TSMC and Intel are investing heavily in backside power delivery.
Here is an accessible article on the topic:
https://www.fabricatedknowledge.com/p/backside-power-deliver...
(Also: high-voltage DC power is commonly used for long-range transmission and does not have coupling issues)