Multiple authors collaborating on documents seems to work pretty well on SharePoint Online and the latest version of Word - I did have some problems with this in the past but seems pretty solid now.
NB I do prefer working with something like git - but for collaborating with people who are never going to use git (even with a GUI) - particularly sales and marketing folks - it is very useful.
NB I do prefer working with something like git - but for collaborating with people who are never going to use git (even with a GUI) - particularly sales and marketing folks - it is very useful.