In reply to just some thoughts...

Mega menus are not always bad UX. If designed well, they can often be easier to navigate than trying to guess which top level category your desired outcome fits into, because it's all right there. This is especially true in cases where the menu items are so diverse they are completely unrelated, like a massive ecommerce site. Look into Edwarde Tufte's "adjacent in space" concept for more thoughts.

Tl;dr: big menus are sometimes necessary and menu management should account for that.