Microsoft has a nice history of making poor corporate decisions. The redmond giant has a habit of moving one step forward and two steps backwards.
In the late 90s and early 2000s, MSN Messenger was the de-facto chat program for Windows users. They gained market share rapidly and took almost all the users from ICQ/AOL. But they slowly killed MSN Messenger with advertisements, rebranded it to a bloated Live Messenger, and the final nail in the coffin was when they decided to switch to Skype.
Windows Mobile 1-6. The UI was clunky but the market share of WM was 40+% at one point in the USA. Then they decided to scrap backward compatibility and abandon the old OS for Windows Phone which lacked comparable features for years.
Internet Explorer used to be innovated at a very fast pace, from versions 1 to 6. That was during the Netscape era, and Microsoft was determined to win no matter what. But after they got 90% market share they got complacent, and dilly-dallied updates until Firefox/Chrome became better Windows browsers than the default Windows browser.
Microsoft could crush Sony’s PlayStation if they really focused their efforts. They control the software that runs Xbox and 95% of PC gaming. However Xbox does not have noticeably better specs or service than PlayStation, and they allowed Gabe Newell (a former Microsoft employee) to dominate PC gaming sales with Steam.