Yeah, the funniest thing is that this adds latency to elements appearing as a stylistic choice.

This is a stylistic callback to slower systems, like BBS on a slow connection, or UIs on a slow computer.

It's also just good UX. A lot of the web today ignores browser defaults, so when you click on a link, there is no visual indicator that you clicked it, like a link color change.

We just don't notice/care because the page usually loads quickly enough.

yeah it's interesting how the visual cues for what would give people the impression of something being futuristic have mostly settled into certain styles even as we move forward in time. what could be the possible reasons for this?

A lot of it is driven by media (movies, games), and falling back to a known style is easier than coming up with something new, which reinforces the style. Whereas if someone comes up with a new flavor, it might not even read to the audience as "futuristic", even if more thought went into it. And coming up with something that's not just a skin on tranditional designs is really hard!

could one argue AR designs should be considered more futuristic?

Fake movie UI also is not driven by the same concerns as real-world UI. It's usually much more a flashy center-piece and then just stuff around it that doesn't need to mean anything, because it's not actually intended to be read like a real UI is.

"Retro-future" is a common term for it, at least in certain blogs and forums.