It sure is!

(I am quite aware of the controversy around the suite but I don’t think the controversy has enough meat on its bones for me to care about it, especially when I barely use these applications as it stands. I just really don’t like LibreOffice by comparison in terms of the UI and overall experience.)

Not OP, but I like OnlyOffice for its keytips support (tap alt and then the whole ribbon gives you live hints for navigating and executing UI functions/buttons with the keyboard). Far ahead of LibreOffice, at least at the moment.