Well, the Footer Sitemap maybe was not that good idea, but why not consider the Header Sitemap instead? HackerNews menu looks good to me.

If the Sitemap structure is too large to be in the Header, maybe it's a good marker to think about reducing the amount of information on your website in general.

Also, I like to have sidebar menus on the left or right of the page for quick navigation, and when I see the webpage on my home widescreen desktop monitor, or maybe even notebook. But I don't like clicking Hamburger buttons each time to expand them. So, personally, I'm fine to always have such menus stay expanded on Desktops, and to be completely absent on mobiles. If I use the mobile device, I'm acknowledged that it's functions are limited by design.