This is very subjective, to me there is nothing that reads better than the academic latex defaults. I would also argue that they look beautiful, but again subjective.

I think it has to do with most devices low DPI as these latex documents historically are made for printing most of all.

I like to save these PDFs in iBooks on my mac and get back to reading them comfortably on my iPad. Works great imho.

Or even better, linking an HTML version.

See: https://news.ycombinator.com/item?id=18865043

Probably, like me, they note that it's a) reasonably okay-looking, and b) way easier than changing it.

What is the font? I keep on seeing it on academic papers.

Computer Modern[1] or Latin Modern. It's the standard font when using LaTeX.

[1] https://en.wikipedia.org/wiki/Computer_Modern

It is the standard font for LaTeX and a sub-standard choice for modern screens and printers.

CM was designed in the late 70s - early 80s. High resolution raster displays were an exotic item at that time. CM was meant to be used for printing documents on the printers of the era, that suffered from considerable ink bleeding.

See the pictures in [1] to see the difference between how the font looks on screen and when printed on the "right" equipment.

[1] https://www.typografie.info/3/topic/22238-ist-die-computer-m...

Not exactly, CM was designed for image setters and very high resolution printing. Early laser printers had resolutions in the neighborhood of 200–300dpi and there are frequent issues with generating bitmaps from Metafont at low resolutions (<300dpi). Some printers had asymmetric resolutions usually with a higher horizontal resolution than vertical resolution since it as easier to do precise positioning horizontally than vertically. In addition, there were two approaches to putting toner on the page: Writes-black (which was used by HP and Apple laserprinters), used the laser to apply a charge where the black should be. When the toner then affixed to the page at the charged locations, there was a little bit of “bleed.”¹ Writes-white (which was used by Xerox and some others), first charged the whole page then used the laser to remove the charge where there should not be toner. The bleed impact was reversed and the result was an anemic appearance to the CM fonts on the page. A hack was created in which an extra pixel was added to the edges of the shapes to increase their size, although this was prone to creating errors in the MF run at resolutions <600dpi.

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1. Not really in the same sense as ink bleed, in which the ink spreads from where it is applied, but more just that the pixels created by the charge were slightly larger than the specified resolution.