Today I did my first advanced spreadsheet on LibreOffice after switching to Linux, and it handled itself pretty well. I had to search for some features on the web at first, but after I got it down, I felt comfortable using it. Also, LibreOffice’s default menu layout is not pretty, but I can find all of the functions with just a click, unlike MS Office’s ribbon menu where I had to click around to find what I was looking for. Sorry for bad English.
You said “in the real world nobody much is doing the latter”.
Indeed, confusing terminology. I consider that collaborative document editing is the activity, cloud hosting vs P2P is the technical implementation.
Like it or not, nobody much is doing the latter because it’s much harder to set up and the available cloud solutions provide a much (much) better user experience. I don’t say this a better situation but it’s the way things are.