AC lines would get large capacitance losses being buried vs. overhead. ElectroBOOM explains why in his vid about high-voltage DC lines starting at this point in the vid.

Granted this is at high voltages in the five-digit range and beyond, and I'm not sure how much that would matter at 240V split-phase that homes typically get in North America*, but that's a technical reason why power lines are still overhead regardless; it's more efficient and with less capacitance losses to have overhead power lines spaced far apart than to bury them.

*Yes, really, I meant what I said, North American homes still get 240V, but it's split down the middle; 120V circuits for things like lighting and such, and normal devices that you plug into a NEMA-5 outlet such as portable space heaters, use a single hot line and a neutral line while 240V circuits for high-powered appliances like clothes dryers, ovens, HVAC systems, and things of that nature, use both hot lines, and optionally neutral in addition for things in, say, an oven or a dryer that only need 120V such as lighting, while the heating elements need 240V in those applications.