As early adopters, many people in the early fediverse had larger sway in the direction that things went. Even now, we have a head start on changing and updating things, adding features, and making improvements to make interaction easier. Many of these decisions are being made for the mutual benefit of the users and ourselves. Large corporations do not think like this as they are driven by gaining users and then exploiting those users for profit. This means we could be seeing injected advertisements and exploitation of user data and content.

Apart from what others have said, just consider the types of people that would join these platforms. While I would encourage anyone to join the fediverse, just think about the low quality of content and thought that the general user on reddit contributes and yet how much more reddit users thought of themselves compared to the cesspools of facebook and instagram users which carry even lower quality discussion. The quality on lemmy now is several times that of Reddit before we made the leap, while the quality on reddit has plummeted. The types of users who would boot lick or care more about their personal inconvenience in the short term over long term prospects and quality are the ones not yet on this platform. Anything linked to Meta is bound to bring a higher proportion of those types of users, as Meta is bound to try and convert their own userbase as well as gather those from twitter and other platforms.