I find very interesting the fact that Facebook had no problem crushing Vine while massively selling Tiktok ads in exchange for potential business in China.
Chinese apps, games and e-commerce have always been their customers.
As for Tiktok, it was spending like crazy on big platforms at the time, and the product didn't seem popular back then, so why not take that sweet money as much as you can.
Probably both
"Facebook didn't kill Vine alone. Leadership issues, increased competition, and monetization struggles all contributed."
If an app like vine was as successful as it was made out to be, why would it's fate hinge on being able to access a contact list from another 3rd party app?