I have Excel and Word 2013. MS think you want to save everything to OneDrive or your computer. Just OneDrive, nobody elses cloud drive, just theirs. It is inconceivable that you would have anything stored anywhere else.

On the Laptop this isn’t a problem, because Google Drive acts like another drive/folder. Fine, can just go to My Computer and save in that handy little subfolder which also happens to be a cloud drive. Google Drive easy to use on MS Windows.
Now I can open that file on my tablet using Excel for tablets (but see next para). BUT I can’t save it to Google Drive. Why? Because Google have hidden Google Drive, buried deep withing Chrome WHICH IS PUBLISHED BY GOOGLE. When you do find it, after a tortuous path, each document has its own folder, with a name like 2he7whdhw8d28hh2hhsnm – I kid you not. You can’t save to these so it appears in Google Drive.

Oh, the same with opening on a tablet- I can’t see Google Drive in Excel, but I can open by opening the Drive, and opening the file that way. But because I can’t save it is read only – so no editing on the go.

Of course Google can’t believe I’d want to receive emailed documents in anything other than the manure-like ‘Google Docs’.

“Its a Word Document. I have Word. Open it in Word”
“I can open it in Google Docs”
“I don’t WANT IT open in Google Docs – you won’t let me edit it.”
“Howabout we download it to Google Drive”
“Howabout you Bleeped texting open it in a programme of my choice”