My understanding is that it's only economical to bury utility lines when there is frequent enough inclement weather to bring them down, which definitely isn't the case in San Jose.
Retrofits in urban areas are especially expensive, because any good contractor knows there's gonna be unknown problems once you start digging.
Most places that have underground electric in the US have it either because it's mandated by local code or because the original developer was willing to pay for it.
Hypothetically, enough bad weather would make burying it economical, but I've never heard of any particular instance where that was the case.
It all results in fundamental cost differences, that were originally calculated based on density and distances, with US being low density/ large distance and the opposite for the UK.
I'm sure there's related consequences with line burial, but I don't know if that's the reason it's so common in the UK.
Wooden utility poles are made from a single piece of wood, usually the trunk of a pine tree. It's cheap to toss a bunch of them on the back of a truck and drive them to wherever, but they're typically longer than a cargo container, so putting them on a ship is annoying.
The forests in North America has lots of tall, straight pine trees but there are fewer forests in Europe and what forests there are tend to have more deciduous forests, where the trees are shorter, narrower, and ... squigglier.
You could have shorter poles and fit them into cargo containers more easily, but now you're stuck with short utility poles. Concrete or metal utility poles are a thing, but they're more expensive.
And anyway, Europe has plenty of farms pine/spruce forests. That Ikea furniture doesn't just appear.
Europe buries power lines because they're considered ugly.
2. I don’t think so. But the way way people describe the geography here is weird. Usually people say it’s the southern end.
3. It’s pretty sprawly, car is king, generally the threat of earthquakes and nimbyism has resulted in low density. I doubt ‘thousands’ though I’m not clear on your units.
4. Highly doubtful. The super-rich mostly live in the suburbs or exurbs of SJ, where it’s cooler (temperature wise) and less urban. Los Gatos, Mountain View, Palo Alto, Woodside, Menlo Park, Atherton, etc.
That took into account what was cost effective from the perspective of large scale deployment, and then individual elements are designed from (and are intertwined with) everything downstream from that. So even if two cities (one US and one UK) were/are nearly identical, the resulting grid is going to end up being laid out very differently.
Reminds me of the joke about cancer risk and lowered IQs and power lines - the mechanism of the damage is insidious - it doesn't act through radiation but through lowered property values.