One reason Windows and macOS are popular is that people know what they are going to get. If you've used one Windows 11 box, for example, you can get on another Windows 11 box and figure out how to use it. It will have the same user interface and window management as the other: the Start menu, the control panel, the desktop, etc.
That's just not the case for Linux. There are several popular desktop environments that are very different from each other in look and feel. For an ordinary user, switching from Gnome to KDE would be quite jarring and it would take them a while to get used to it. For power users and tweakers, that diversity of options is an attractive feature of the Linux desktop. For ordinary users, it is a deterrent.