He/She Will
just as soon as they have to open a .XLS/.XLSX or .DOC/DOCX that that has any complexity to it. You may detest MS Office, but you have to live with its files unless you have no interaction with any part of the outside world and no legacy files of your own. The Open Office variants are still not up to the task.
I'm not sure where "everything's in a browser" land is, but it's nowhere I've been or even seen in outside of blogs like this.