The state had the forsight to lay tons of conduit a decade or two ago whenever they do road work so that there's plenty of space for bandwidth upgrades and what not across the entire state.
For huge swathes you can have lovely ancient old ADSL on your copper phone line or Comcast via cable. Oh and all Comcast plans in the Bay Area, regardless of what the marketing says, have a 1 TB bandwidth cap and charge for overages up to 200 dollars on top of your monthly bill, unless you pay them an additional 50 bucks a month to get the _actually_ unlimited option on all of the plans offered. As you can imagine, many of us living here routinely blow through a terabyte of bandwidth - just one cloud connected security camera can eat a third of it easily.
That’s literally it for most people.
> Silicon Valley, by contrast, seems like some parody of American municipal mismanagement.
And not hear "You were saying something about best intentions?" from Jules in Pulp Fiction.
ex-Verizon areas that aren't rural generally have fiber coverage, excepting Finn Hill. They committed to a bunch of smaller suburbs to have 100% fiber coverage by 2008, which mostly got done. Sadly, they only go up to 300mbps symmetrical for $50/month iirc.
Cable internet is the only game in town in most of the valley unless you want 40mbit DSL.