I think it's more in that each platform has their differences as far as consumption, and possible behavior setting/modification, in which they're both detrimental. It's not secret that algorithms are used to keep the user engaged, and that so-called ragebait is a huge engagement driver. Facebook is somewhat of a link aggregator meets microblogging (ie status updates), while tiktok just feeds an endless loop of short videos. I would imagine (though I don't have stats or sources) that videos keep people glued to their screens more effectively (easier than reading), and could be more troubling.