After buying a chromebook a month ago I am completely convinced this came a few years ago and no one paid any attention as it wasn't the vision they had of the Linux desktop.
I was blown away by how nice ChromeOS is to use, how seamless everything is, and how well Crostini (I think it's called this) works at running Linux programs. ChromeOS is honestly the single best Linux experience I have ever had.
I noticed but I don't think this is a satisfactory Linux Desktop. It goes against many stuff Linux Desktop proponents could be fighting for, mainly privacy and controlling one's computing. The main point of the Chromebook is to make your computer a thin client to run your computing on Google's servers. I think computing should go the opposite way. It's fast and has no virus though.
As for the market share, I know nobody with a Chromebook around me, I don't think it's a big thing where I am.
Technically true, but not what is meant by that term.
https://support.google.com/chromebook/answer/9145439?hl=en
Eg Instructions on how to run Firefox on ChromeOS with Linux mode
Also, I had a System76 laptop for work once and absolutely loved it. I tried to buy it when I left, but they weren't happy about my reasons for leaving and refused to do so.
Really though, I think it's for you to decide. It's not like there's a standards body with a rigorous criterion on if a given year is "Year of Linux Desktop", which is perhaps OPs point. Personally I think that 2013, when Dell first started selling the XPS 13 with Ubuntu was the Year of the Linux Desktop and I personally think that we've actually lost the plot in subsequent years.