There are 1 billion active users on Instagram and those users were invited to Threads using an existing account. Celebrities, businesses, streamers, etc. all popped up on Threads within the first few hours of public release.
I'm a big nerd and just learned about the fediverse within recent months. Everyone else I know who uses Twitter and Threads have no clue what Mastodon is.
I know it's ignorant, but all I can imagine when using a bidet for the first time is shooting my corn hole with a jet of cold water, not knowing how clean it is back there, and using a towel to dry off only to find watered down shit on the towel.