Any word processor that can't round-trip Word files without messing up formatting (and specifically headers/footers, track changes, and text boxes) is not going

Any word processor that can't round-trip Word files without messing up formatting (and specifically headers/footers, track changes, and text boxes) is not going to succeed for people who collaborate with others in Word. I've tried every online word processor and many Linux ones, and they all fail at retaining this moderate-level formatting.