Onboarding and retention issues are not unique to Hive. Friend.tech and DeSo which claim to be decentralized social networks also suffer similar difficulties. Not sure if DeSo's 99% failure to hook first-time users also happened on Hive. The two primary reasons are onboarding difficulty and the feeling of landing on an alien planet that you don't know anyone. Good for those who have been invited to the platform with strong community support. Those who stay not knowing anyone seem rare.
As for the above chart, it appears that both Similarweb and Coingecko are not aware that Hive Blog, PeakD, and Ecency are front-ends built on Hive. It's good to see three Hive platforms included in the list of 15 most popular decentralized social media in 2023. If you combine all of them, you will come up with 521,000 plus users and Hive will occupy the 8th place.
Though Odysee is ten times bigger than Hive in terms of "average monthly unique users," the number is insignificant compared to the Web 2 platforms such as Facebook, Instagram, and Twitter. These platforms "hosted about 2.98 billion, 2 billion, and 372.9 million monthly active users, respectively." This tells us that the claimed migration from Web 2 to Web 3 is either not happening or the transfer is moving too slowly.