Can you explain why you think so? it's not self-evident.
WordPad was a quick and easy way to view/edit simple Word documents. When you double-clicked a .docx, WordPad would let you read it (albeit with some formatting issues).
Now when you click a .docx on a fresh Windows install, you get a generic “what app would you like to open this with?” pop-up.*
This leads the user to google free ways to view Word documents, leading to LibreOffice.
* Site note: I’m very surprised Microsoft doesn’t use this as an opportunity to sell you Office.