Having constant exposure to social media versus occasional, sporadic/segmented access will greatly influence how body image will be perceived and affected.
I agree that the problem is in how it's used, but you could say the same thing about heroin, predatory loans or casinos. It's not reasonable to put all the weight on personal responsibility when screwing with the process of thought is one of the most lucrative enterprises in the whole planet to begin with.
I think the biggest difference is with TV, while a teenager would still be exposed to other teenagers with a body image that could make them feel bad about their own, it would still be within the context of fiction and at lest some kids could write it off as “those are stars” or “that’s fake”. In social medial, the new stars are influencers who otherwise seem like normal people so I feel the pressure to try and look like someone else is higher.
As those became more addictive, they are an actual issue for actual real people.