Travel. Near and far, it will bring you new perspective.
Reading. When I was young, I would take 3 books at a time from the library: a fiction, a non-fiction, and and a (auto)biography. When all were read, I would return and repeat. The books weren’t chosen randomly, but to my interests.
Volunteer. The really young and the really old are the best. Preschool and nursing homes. All the depth is there to absorb.
Never ignore the “uninteresting”. Therein lies your best chance to advance. If you take @janbb‘s advice, concentrate on the articles that seem to not interest you. They hold information you didn’t need to know, information you didn’t know, introduce idea’s that you’d not considered, or are garbage, and you know that.
Depth comes from constant soundings.