An opposing anecdote: While using the Office web apps, I have rarely seen the "you need to open this file in the Windows desktop version of XYZ to edit the fil

An opposing anecdote: While using the Office web apps, I have rarely seen the "you need to open this file in the Windows desktop version of XYZ to edit the file" message in the last year and a half at Microsoft, a company that intensely uses Microsoft 365. In every case that I can recall, this message showed up in one of 2 cases: 1. Macro-enabled files - there is no VBA or .NET programmability for the web version. 2. Files protected with M365/Azure information protection (DRM/IRM). I don't think either of these scenarios are likely to occur in a charity/nonprofit, which was the original post's concern. As for me personally, I hardly ever wanted to edit files in either category intentionally - the macro-enabled files are old archival docs and the DRMed docs are announcements from executives. > And I don't think it supports the older Office files at all. True. M365 can convert .abc Office files to the .abcx format, save the converted copy, then open it for viewing and editing. That all happens in 1 step but is not the same as supporting the old formats to begin with. > I mentioned that to the secretary and she just laughed and said you can't do collaborative work with the online version when everyone else uses the desktop version. Ironically, I find that to the extent this is true, that's because the desktop version has fewer features. Make a comment on a Word doc? If you did it in the web version, your collaborator gets an email with the comment text, and if they're using the Outlook web or Windows desktop versions, they can even reply to the comment from within the email preview without having to click Reply or open a link to the doc. But if you did it in the desktop version, all your collaborator gets is "Comment previews are coming soon to the version of Word [you] used!" where "soon" has been soon for at least a year and a half.