ppt to doc conversion was actually pretty common back in the days of original MS Office formats and was used to export the textual structure of PowerPoint presentation as a Word document. Certainly still doable in latest MS Office, just now it's done typically as pptx to docx conversion instead. In any case, you can still work with the older binary formats just fine, they are just larger in file size and might not support every type of formatting, available in latest versions of the software.
Updated: August 16, 2023