It does handle many orders of magnitude more users than this thing does though. As a site that is the source of many hugs of death, it's serving a hell of a lot of traffic, mostly successfully.

It could serve even more traffic if it was less bloated of course.

EDIT: Some random stats from 2019 suggest that they're handling ~1000 pageviews a second on average over a month, and a view can take >100 requests to load. Combine with surge load and you're dealing with some serious requests per second.

Over 100 requests per load? That has to be static files like images, right? Do they not have a cache system for that (like what Cloudflare provides)?

Articles, thumbnails, comments, votes, awards, users, I'm sure it all adds up considering the dynamic nature of what each user sees. And they do do a lot of caching to make it work:

https://redditblog.com/2017/1/17/caching-at-reddit/

A friend worked on a project that reached several hundred requests at one point.

Basically they had a 10 request component. Only one on the page so even though it wasn't that efficient, they didn't care.

But then their PM wanted 20 of them on a page. It was a Scrum team so velocity mattered, so they just had a for loop generate 20 of them.