I've seen ONLYOFFICE used on Nextcloud instances and I haven't seen Google Analytics loaded up. Do they provided a cloud/hosted version that has it? But agreed - I was impressed with ONLYOFFICE.
They have lots of different offerings. I looked at personal.onlyoffice.com, their free hosted version for personal usage, and they load Google Analytics not just on the landing page, but when you open a document as well.
