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.
How is it Microsoft’s fault that the LibreOffice team fails to properly support its formats? Others can do it.
The formats are “quasi-open”. There’s still a lot of proprietary stuff in them. Or undocumented or poorly documented things. MS didn’t really want it to be an open standard.
Being compatible with them requires a lot of work to reverse engineer the formats. Some companies make licensing deals with ms to get access to better docs but must keep their code closed. Something libreoffice can’t do.