A pretty important point is that Linux doesn't come installed on many devices. For most people, they buy a computer with Windows or Mac already installed and they're satisfied with their experience. They don't feel the need to find a distro, mount a USB stick, navigate through the BIOS, run an installer that wipes their hard drive, and relearn another operating system when Windows and Mac does everything that they want. When Linux comes pre installed on devices such as the Steam Deck or Chromebooks, Linux usage soars, though these devices have to use Linux because they need a heavily customized OS for their specific purpose. Laptops and desktops intended for casual use that come pre installed with Linux are far less common, so for the overwhelming majority of users, Windows or Mac is what they get and what they end up using. I wouldn't be surprised if Microsoft switches from charging for Windows to paying manufacturers to put Windows on their computers to get users into the Microsoft eco system if Linux became an actual competitor one day