@santiago Glad it's not just me! Haiku is too tiny on my HiDPI 2K display and I had to change the resolution to 1080p to be usable. My eyes are old too.
It's a great way to test which UI elements aren't properly scaled, though. Like the tiny toolbar icons in Pe, the tiny mouse cursor, and one of the scrollbars in HaikuDepot. (Once I'm familiar with the code, I'm wondering if that's an area where I can help contribute.)