A family of Microsoft word processing software products for creating web, email, and print documents.
Placed images are downsampled in both Word for Mac and Word for Windows. As I recollect, Windows downsamples to 200 d.p.i. and Mac to 400 d.p.i. To avoid downsampling altogether, you need to use Acrobat.
To suggest that Word work differently, please choose File>Feedback>Send a Suggestion in Word for Windows or Help>Feedback>Make a Suggestion in macOS. You can post your idea and others can vote on it. Microsoft uses this feedback to prioritize their programming.