

In addition to cost (as everyone else said), work and worker qualifications. Working on underground lines requires special confined spaces training and certification, because it is more dangerous, could deal with not just electricity, but potentially hight temperatures, water, sewage, toxic gas, lack of oxygen, etc. There are even fewer people willing to do that compared to riding a bucket to the overhead lines.
Source: Worked for electrical utility



















IMO those paths diverged in web development somewhere around 10 years ago. While you could write efficient websites using standard HTML features and minimum of JavaScript (the good-efficient path), companies and developers started going towards various frameworks, which were “faster” for developers to use, but usually at expense of performance on users’ side, numerous dependencies, and security. Each framework trying to do its own thing, and some are conceptually entirely different from bare HTML+JS.