I have not yet figured out why anyone would choose this behaviour in a text editor. You have to press something to exit the delimited region anyway, whether that be an arrow key or the closing delimiter, so just… why did the first person even invent the idea, which just complicates things and also makes it harder to model the editor’s behaviour mentally? Were they a hunt-and-peck typist or something?
In theory, it helps keep your source valid syntax more of the time, which may help with syntax highlighting (especially of strings) and LSP/similar tooling. But it’s only more of the time: your source will still be invalid frequently, including when it gets things wrong and you have to relocate a delimiter. In practice, I don’t think it’s useful on that ground.