This is the idea behind the “new new” tab, which is an opt-in experiment at the moment and would eliminate “unread” for a combined /new route (which could be filtered to topics/posts if desired)
Related topic: The "new new" has been enabled on Meta
It might not be useful day-to-day, but it’s shown to returning users if they haven’t been around for a while. The idea being “this is the most active stuff you missed while you were away.” I use it to catch up occasionally.
Hot is very new (only added within the past week) and still something we’re experimenting with (the algorithm might change, we’re going to try including AI summaries, the topic list layout may be different, etc)
So I think you’re probably right, but we’re still figuring it out.