Well, you can get a Galaxy J7 prime for about $200, and the Galaxy A8 and OnePlus are around the 400-500 mark. Much cheaper than a decent laptop (which over the past 10 years of laptop shopping I've found hovers around the 1200-1500 mark). Sure, it's a consumption-only device, but
that's what most people do with their computing devices outside of work! For the 3 times a year the average person needs to actually do something that requires a proper keyboard and decent screen, they'll just use their work-provided machine, or borrow a relative's computer or something of the sort.
This is especially relevant in 3rd-world countries (I'm from one, so I get to call us that!) where people have much lower incomes, and proportionally less money to spend on tech. When you have to choose between a $500 shitty PC + $100 featurephone vs dropping 400-800 on a decent smartphone, you often go towards the phone side. ESPECIALLY if your job gets you access to a real computer.
EDIT: I wouldn't buy a J-series samsung (I need real amounts of RAM on my phone), but it's perfectly adequate for most of my relatives.
EDIT2: I use Syncthing for my own syncing (I have more data synced than literally any free service allows me to store), GSuite business for my own bulk offsite storage, and oneDrive Business/SharePoint for work stuff.
Ignoring the points
@evernessince mentioned, the obvious, and most important missing bit in the statcounter info is the complete lack of total numbers. % changes in tech often means just changes in growth rates, and a lot less people abandoning a platform for another.
OneNote is. Real OneNote, not the bastardized, useless POS that is the UWP app.
I guess Excel and PowerPoint are good too, and Work is a passable word processor... Outlook's passable too...
If you work with other business, people or states, you often end up using MSOffice just to keep collaboration sane. Especially if you use Excel beyond =A7+B7. A bunch of businesses have moved to 10 as well, like my dad's small consultancy. It's been great for me, since I don't need to worry about updates in particular.