The entire point of footnotes is that they have been moved out of the main text because their presence would negatively impact the flow. If most readers are expected to want to read them then they should just be part of the text and probably not even in parentheses.
Right, but it should be easy for the reader to decide whether to divert to the additional content. A superscript number tells you nothing about the additional content. Whereas on the web, link text or a details summary can help you make a decision.
