Yes, it is set to `normal`. It is reasonably readable but not excessively reasonably ;)

I don't think browser vendors are the right people to blame though. Their job is to give the designer enough control and they mostly succeed or sometimes don't (https://www.smashingmagazine.com/2012/12/css-baseline-the-go...)

But you certainly cannot expect them to come up with optimal default working for every single site out there.

So setting proper line-height has to remain the site's responsibility. And something as simple as unitless 1.4-1.6 would improve readability with any "regular" font.

Given that HN isn't exactly famous for using fancy fonts, which isn't a bad thing at all. ;)