And yet ...
I first installed Ubuntu in 2006 ... I was VERY impressed when my penguinhead brother came up one Christmas, popped a 6.10 LiveCD into my Windows box, and within 5 minutes had a bloody impressive desktop GUI up which had found my network card, and connected to the internet seamlessly.
Wow ! I thought. Seems we're pretty much there with Linux as a desktop contender (I was more aware of the server capabilities at that point).
So now, in 2018 - 12 years on WTF happened ? And why does nobody (or nobody that wants to go on record) see that the biggest single "killer app" that would make Linux desktops a much more viable reality is something to replace Outlook - an enterprise level email and calendar program ? Because if you can't replace Outlook, you'll never get as far as Word, Excel and PowerPoint no matter how good LibreOffice is (and it's quite good).
I'm currently rocking Mint, but Thunderbird + Lightening are nowhere near as good as they should be.