The year of the Linux desktop will happen when a large (EDIT: large, CONSUMER-FOCUSED AND CONSUMER-FRIENDLY) company decides to donate a remarkable amount of resources to the development and maintenance of a specific distro to make it user friendly and give it the feeling that someone who actually knows better than most users is taking care of important stuff in the background.
TBH: Most private users aren't really using many programs. They are running chrome. Maybe an email client, but even that is declining. They are looking at pictures with the standard photo viewer and maybe at some PDFs and sometimes they are writing a letter and print it? Linux totally can do that.
That's not completely accurate. Remember, a lot of people want a full keyboard for typing; and an iPad with a keyboard is way more expensive than a mid-range Chromebook. Plus, a whole generation of students are growing up and entering the workforce having used nothing but ChromeOS for their entire middle school and high school careers; for them, a Chromebook feels very familiar.
Microsoft is VERY close to losing every install advantage they have. Gaming, corporate, devops, and government are the only use cases their leads are still in any way commanding in; and they're fiddling while Valve puts the finishing touches on Steam OS, they're about to lose their tenth consecutive K12 graduating class who will go into the workforce more familiar with ChromeOS than Windows, devops is increasingly moving toward web portals, and government...well, let's face it, that's not a particularly lucrative single game to win.
Google has already eaten Microsoft's lunch and dinner. And now they're about to split Windows' breakfast with Valve. Unless they make some major changes, and quick, Microsoft is going to go into the 2030s less relevant than they've been in decades.