In the paper you link, they clarify that the association between depressed mood and social media was much more significant when testing against problematic social media and internet use. Social media isn't inherently more harmful than other harmful vices. The paper struggled, and in my opinion failed, to show proper cause vs effect when seeing where a cycle of problematic social media use vs depression starts. Teaching ways to manage and control use time, and address underlying issue that would encourage escapism through the internet, is the only meaningful thing you can do.

My perspective is that for all current and future generation of children, removing them from social media will be harmful than helpful because of how isolating it will be. Some foundational social skills are now built online instead of outdoors. With the hypoconnectivity, kids today have to learn skills that adults today didn't need to earn. Anecdotally I gained an appreciation for online social skills when I got a smartphone the senior year of HS. I didn't realize how much I had been left out of things simply because I wasn't able to join social networks built on Snapchat and Instagram. Discord has become the main network for most kids now.