@nprofile1q... I think M365 fails at the sharing part though. I got a form to fill out via email, so I uploaded it to office.com, filled it in, and shared it with someone else in the company via the web interface.
They couldn't open it.
I tried exporting as PDF, but security policies prevented it, because it detected sensitive data (it had my home address and phone number).
I could save it to OneDrive, and download it from there, but then I couldn't open it myself on a Mac (I was able to open the original without a problem).
In the end I just downloaded LibreOffice, edited the original document, emailed it back as both document and PDF form, and then they could finally open it.
I don't know what MS has done here, but they seem to have completely broken compatibility with their own format (or maybe they broke the security checks, and sharing of sensitive documents doesn't work anymore, I didn't try to debug why the other person failed to open it). I would've thought that at least the web version (somewhere on SharePoint) would always work. But actually LibreOffice is more compatible than MS's online suite...