This is a good question, thanks for asking. The Title field is a specific type of Rich Text field, so it works the same way under the hood that a Rich Text field does. A Rich Text field allows for multiple blocks of content where you can select different options, so the output is an array of these blocks. With a Title field, you can only add a single block of content.
So I understand that it might seem weird to have the output be an array, but that is only because the Title field is a specific type of Rich Text field. This way, the Title field can use the same helper functions as a Rich Text field (RichText.asHtml, RichText.asText, RichText.render). Here is the documentation for templating a Rich Text or Title field with Javascript.