I don't think the problem there is the pagination (or lack thereof). This page has 103 comments right now and is 204K (31K compressed).

HN is pretty minimalistic, but the point is that text data isn't really what makes requests very large. For reference, 2MB is enough to include an entire book and then some. All of Dune is about 1.7M uncompressed in epub format (and ~1.1M compressed as an epub file). HN threads, Jira discussions, etc. can get pretty large, but I have not seen any yet that have started to approach the size of Dune.

Images might add more data, but those can be loaded on-demand when scrolled into view pretty easily.

No, relying on mega-frameworks and non-optimized graphic images are the express train to large request sizes. Don't forget video.

Indeed.com's search results are almost all text. Maybe a company avatar. No reason it can't provide 100+ job listings per page rather than 10-20.

I don't think that is a bad thing, considering that a YouTube video in HD would be 500MB and people flick through them like web pages.

I agree with OP that if you are on a powerful machine with fast internet it would be better just to load a massive HTML document of list items.