Disneyland, Disney World, and The Woodlands, TX (where I live) all require 100% buried power lines. The visual difference when crossing in or out is quite apparent. Buried lines improve quality of life for residents and visitors.
Related: https://www.npr.org/2021/07/21/1019058925/utility-bury-power...
This course of action appears to be a result of a recent wildfire that may have been caused by PG&E power lines
Underground laying of high voltage lines brings very very high costs as well as greater dielectric losses, and it costs a lot more to find a fault and dig down and fix it. That said, many downtown areas went underground decades ago, and also placed the wire in underground tunnels with other services. The underground mesh is a very comple beast in many places.