Google may be the most popular option for real-time collaboration but is not the only one.
OnlyOffice and Collabora Online Office are two well-known open-source options you can host.
Both work well and are free-to-use apart from hosting costs.
There are other open-source collaboration tools out there though.
Getting into the world of self-hosting opens up endless opportunities for your IT department!
Start by getting your server at https://www.hostwebis.com/