“We recommend Microsoft Word for rich text documents like .doc and .rtf and Windows Notepad for plain text documents like .txt.”
WordPad shipped free with every copy of Windows since Windows 95. Its replacement for rich text is Microsoft Word, which costs money every year. Earlier this year the Qbot malware abused a DLL hijacking flaw in the WordPad app, so Microsoft gets to drop a liability and upsell an Office subscription in one move.