If you have multiple forms enabled for a single category, it isn’t intuitive that there is a dropdown for you to select a form. When you create a new topic, it automatically populates the first form template, which again, if you don’t know what you’re looking at, then you wouldn’t realize there could be other forms.
When you deselect the form, you do see the text “Select form templates” which is clear to me that there is a list of form(s) that I choose from. The composer still shows the form even though one is not selected. This is where I would second, @iamntz about having the option to switch to no template.