This is a hidden gem. The 2021 revision includes a ribbon interface that looks exactly like Office 2013.
Office 2013 fully supports DOCX, XLSX, and PPTX as default formats. It also handles PDF editing and opening. Older versions (2010) struggle with some modern OpenXML formatting, while 2013 handles it flawlessly. Office 2013 Portable Word Excel Powerpoint -
Some reputable software vendors (like PortableApps.com or LibreOffice Portable) do not offer Microsoft Office due to licensing restrictions. However, tools like WinToUSB (entire Windows on a drive) or Ceedo allow you to run a full Windows environment from a USB, into which you legally install Office 2013. This is a hidden gem