Seems like a definite win to me? Maybe your usability desires are different than other users desires? In the case of an autohiding header - it doesn't seem like a big reduction in page visibility?
I straight up permanently remove most sticky headers with Ublock Origin. 90% of the sites I read content on, I didnt get there by internal site navigation, I got there from a kagi search or HN link. The rare exception are documentation sites; I use their internal navigation often. Thankfully, though, very few of these sites use sticky headers. I just quickly scroll to the top or use the pagination buttons at the bottom.
This might be targeting a minority of users - it’s design for power users. I’d expect HN to be supportive of this sort of design.
You'd expect.. But please listen.
Its even worse on the phones where you sometimes get header plus some commercial and maybe a cookie banner, interacting with each other trying to figure out how to close them in order is a puzzle.
There have been maybe 1 or 2 sites out of all that i have visited, that I didn't immediately hate the banner.
To me it become a "site smell". So if I have an option I'll go elsewhere for my needs.