[Closi]

As someone that heavily uses PowerPoint collaboration - I would say that it's got a lot better and keeps getting better. It's not perfect, but it's much better than it was two years ago (and the number of conflicts keep coming down).

But yes - much better than Google Docs, which has some frankly bizarre limitations each time I try to use it.

Excel collaboration on the other hand... good luck! (I suspect an application of the complexity of Excel just won't be able to be easily made collaborative... Google Sheets manages it, however it is a much simpler app that can handle less data and has much less functionality).