I moved to office 365 from my now ancient office 2009, my main reason is probably outlook, the rest of the suite is a bonus.
You also get 1TB of storage with fast access. I can upload to OneDrive @ > 100Mbps. Some of the other online storage vendors I trialled were very sluggish in comparison.
One drawback with OpenOffice is that it cannot save to current Microsoft Office formats. LibreOffice can and is more widely used.
I've used Libre Office for several years now and have never had any problems with it. I generally find it excellent. https://www.libreoffice.org/