Replace “Office” with Photoshop, Autodesk, Altium, etc. and it becomes very clear why this isn’t true. The Big Guys(tm) aren’t popular because they’re Windows and macOS programs; They’re popular because they do practically everything and no alternative comes close.
Sure, there is the bit about market dominance which leads to people learning just that tool which leads to further dominance (this is true of Photoshop especially). There’s also the bit about tools not getting better if no one uses them. But one would be hard pressed to find programs as capable as those mentioned earlier.
I think this kind of attitude is why Linux on the desktop will probably never be mainstream.
It does not need to be mainstream to be useful.
- in Excel, you can clear conditional formatting rules but you can't manage them. And text in text boxes turn into images that can't be edited, only moved.
- in Word, formulas turn to images. Complex tables break.
- Visio... well, there is no web app version of Visio.
not the same but you have Office 365 that does a reasonable job for most documents out there.
On the other hand, not having Office is kind of a feature, it makes you learn better tools :)