It’s true that info isn’t available at a glance, but you can click their icon and get a glimpse of some of their profile.
As far as the latest active post in a category, if you click one, it’ll show you the latest active topics. Do you mean at a general overview level? Discourse also has more granular notifications if you want to keep an eye on certain categories more than others.
Thank you for your feedback—we’ll be collecting a lot of it over the coming days and see what iterations we can make for folks 