I’d say it’s pretty relevant. The ad-funded tech giants are valued based on continued exponential revenue growth. This can be accomplished by a combination of growth in user count and average revenue per user (ARPU). Both of these factors are supposed be present. A small % annual user growth for Google or FB is tens of millions of users. TikTok beating that from a much smaller base is impressive and the monthly graph from the article highlights that Google and FB are probably not getting exponential user growth.