The point is pure psychology: The internet and other advanced "communication" technologies has caused a loneliness in people due to the lack of genuine human interaction, which is partly due to its inherent nature and partly due to the intense commodification of everything on it from large corporations such as Google.

The result is that systems are designed more and more to appeal to the need of the person to gain attention. Twitter itself is much more of a platform where people fight to gain attention for themselves because it is the single aspect of human interaction that has been "gamified" in order to keep these platforms running in exchange for ad views. It is a pathological nature of human interaction that has become a sort of mental drug for users.

The final result is that people have a knee-jerk response to continue these systems because they have become psychologically addicted to seeing their own little posts as encapsulations of their voices, with all the upvotes and views satisfying a single component in their minds of human interaction -- a component that is meant to be part of a much larger complex of behaviours that constitute real, genuine human interaction, and which no longer exist due to our collective support of a consumerist system that places no value on the essence of humanity.

Mastodon still has character limits for posts. There are ways to write longer messages but they require custom clients or integrations.

So threads like this are still among the easiest of ways to broadcast a larger thought into the fediverse.