I am sure that YOU do. However, (1) I often start something and then change my view of the best format for it - mindmaps, word documents, evernote records, an even handwritten, and (2) my intended audience can change too - something purely for me, might ultimately be shared with colleagues, students, editors and so on. Flexibility is therefore key, so telling me to decide before I start isn't very helpful.
Yes, documents of any format can be stored as attachments, but when that happens there's little advantage to using Evernote over the usual Windows filing system - all EN is being used for is a glorified filing cabinet.
As to exporting to HTML, I have yet to do this without having to reedit the document because of the number of formatting errors and embedded characters.
Sorry, but I agree with others that an "export to DOCX" is long overdue.