To reiterate threeseed’s point: the user wants the website to work well and work efficiently. They don’t care if it’s HTML or an interactive app. In a lot of cases, the web works better when pages are served as plain static HTML.

Websites also work better, IMO, when every page doesn't use remote resources on 10 different domain names hosted by 3rd-party vendors. This is one of the reasons I use Vultr instead of Digital Ocean: instead of locally hosting their own JS pages, DO uses 3rd-party services. (Maybe they don't have a choice if the 3rd party requires it.) Whereas with Vultr, I only had to enable one or 2 domain names and the whole site worked. It's a much better experience for the user IMO.

Sure, a simple marketing site for a local restaurant can work with only HTML and CSS, but practically all of the top 20 most popular sites would cease to function without JS.