Google converts word docs though and you can also easily convert the other way. As for data, that's not something I worry about, it's the schools data, not mine. If their happy to use it then it's good enough for me.
We also used Moodle quite extensively before the Gsuite and it does have some really good features if properly maintained and set up. However, I much prefer Gsuite.
Edit: since home schooling has kicked off, Google have added a new feature in classroom, the ability to set up a Google meet (Video Conferencing) with all of your students. Really useful and like most of their stuff really simple.