For a long time, the track changes function in .docx documents could not safely be used in LibreOffice, at least not when collaborating with someone using Microsoft Word, as changes would simply disappear. Fortunately, this has since been solved. Even so, I occasionally experience formatting issues when pinging a document back and forth between the two software suites, notably in footnotes. More generally, when preparing copy for submission to a publisher you don’t want to take any chances: if they ask for a Word-formatted document, you had best do your final checks in Microsoft Office.
For Linux users, Office 365 has long appeared to promise the solution: Microsoft functionality within the browser. If I recall correctly, when it first launched its features were still a little limited. I recently got hold of a licence through work, and they seem to have made large strides: the ribbon looks impressively comprehensive, and even the speech-to-text engine works surprisingly well without any voice training.
For some reason, however, the one reason to turn to Microsoft Office in the first place, collaboration, is crippled by the absence of that key function: track changes is only available in the desktop distribution. This is the more disappointing because I am actively involved in a book project with a team sufficiently large that we desperately need realtime collaboration, and the team’s technical expertise is sufficiently diverse that any solution that does not involve native .docx editing is out. There seem to be a number of commercial solutions on the market, but if Microsoft can’t get it right I’m skeptical (and I could never get the team to splash out on software). Are there any other solutions out there?