I will broadly answer for right now because I'm running short on time, but you can ping me later if you need/want clarification. Generally speaking, Steemit is unlike any other social media platform so I wouldn't necessarily look towards similarity of platform. I think the Steemit difference is what drives its competitive value against Facebook and Snap.
Although it's true that FB/Snap have distinct attributes, Steemit makes you money. For a vast majority of potential users, that's all they need to hear!