Many are suggesting that TikTok would be overvalued at $50B. If that's the case, do you believe FB is overvalued at $662B? Instagram, as of 2018, was estimated to be worth around $100B on its own (with about 1b MAUs, versus TikTok's 800m). TikTok seems at least equally addictive, and its algorithm does a fantastic job at quickly showing good content that matches your interests.
TikTok has been very good at focusing on new content discovery first when you open the app, making you swipe left to see the people you follow second—this is the opposite of Instagram. If Facebook does manage to pull people like Charli D’Amelio and Addison Rae to Reels and makes them more prominent, it would really be interesting to see two different philosophies compete against each other.