On top of being preinstalled, we also need google search-able instructions that avoid the terminal altogether. People are afraid of the terminal, it doesn't matter why, it just is.
Currently, most solutions to linux problems come in the form of terminal commands. We would have to start creating a whole new troubleshooting forum where instructions avoid the terminal and are just lists of buttons to press in a GUI. Probably helpful screenshots too.
Of course I have no idea if some things even have GUIs at all, like configuring user groups and permissions or firewall settings, someone would need to make them. Not to mention every DE or program would need a different set of instructions, GNOME or KDE, firewalld or iptables. It'll be a lot of work.
What if websites decide that chrome users earn much more ad revenue and start forcing users to switch with those "This website only supports Chrome" error messages? What if this practice gets popular? I'm sure there are ways to get around it, but the average users who bothered switching to Firefox at all, will just conclude that anything except chrome has a bad browsing experience.