Emails were designed to use plain text. You can send formatted emails using HTML, but there is no guarantee that the recipient's client will interpret it correctly. Pasting in from a version of Word that does not use HTML formatting is not going to give the results you expect. Complaining about it is like complaining that your DVD won't play in a VCR.
Bill Gates retired many years ago.
If you want to send a Word-formatted document, send it as an attachment.