If this is going to federate with the fediverse then why wouldnt I just sign up for a Mastodon instance and use an app/instance that doesn't shove ads in my face?
Same reason person who didn't hesistat to make an Instagram account after seeing it is owned by meta and then didn't hesitate to install threads after seeing the permissions wouldn't. They don't care. They are just excited to have a Twitter alternative and none of the stuff like ads or data mining or algorithm based influence on users matters. Why would the average person go through hoops to access threads when the officla way is so much easier.
All the famous people they want to follow are there, and they couldn't be more excited and hyped. They don't want a departure from a billionaire run social media. They just wanted a different billionaire.
It's definitely not for our benefit. My suspicion is they want to try and get hold of the users who have refused to join in and get data minded along with everyone else. First step is meeting people involved with the fediverse and then having them sign NDAs to discuss who knows what. Then probably try to get influence over the project like Google did with Android so then fediverse over time becomes synonymous with Meta and becomes increasingly dependent on them for funding and development.