For once, the money is genuinely not the point, from any point of view.
The stated purpose, and I think it will accomplish this, is that no one running a bot network will pay this for their bots, so spam reduction.
The likely ultimate purpose is to have the user’s payment info saved to reduce friction for giving Twitter money later on.
The problem though is that they’re adding this friction on to the beginning, so as a result I think the most prominent actual effect is going to be 80% of free users (real ones) are gonna kill it then and there.
Some people don’t like when it’s too quiet. For some it’s uneasy, for some it makes it too hard to stop your mind from wandering. That can make it hard to sleep or hard to focus on a task. White noise is noise that makes it not quiet, but isn’t so loud or too full of meaning to be a distraction on its own. Most people use something like ocean waves, running water, rain, wind noises, the warp core noise from Star Trek, etc.