I don't have an Instagram account, so please excuse my ignorance, but I was under the assumption that a lot of content on Instagram is "sponsored content" anyway? So you're looking at ads anyway?
I just opened Facebook and here's the top "suggested post". Of course it's a "news" story, which is itself just a repost of someone's Tiktok video. The Tiktok logo is prominently displayed in the tumbnail.
In between all that content, is Facebook Reels. Most promoted Reels are just reposts from Tiktok. There was literally a "Content Creator" named "It's gone viral on Tiktok!" that for a while was the most commonly promoted Facebook reel I would see.
Edit: here's a screenshot of Reels: https://imgur.com/a/OhVvbSf