Oh...so MSOffice is cross platform? Opens Libre/OpenOffice etc....hmm...no it doesn't.
MS Office runs on Windows, Mac, common Linux distros, and Unix.
That seems pretty cross platform.
Libre is the result of the Open Office initiative. It has matured into a good product. IF you have no need for automation features and you are not dealing with complex spreadsheet models, it is a good choice. For most home users, Libre is sufficient for your needs. Impress is still vastly inferior to PowerPoint, but if presentations are not a focus, then this doesn't matter. Writer holds it's own against Word. Calc has all the basic functions of Excel, but lacks the modeling and statistical functions. However, these are used only by serious professionals. Most people will never miss them. Obviously there is no OLE support in Libre.