don't forget office suite:gdoc, and conferencing: hangouts/meet/whatever they force down your throat tomorrow. this is specially pernicious as they are actively using it to undermine Firefox in the workplaces. their proprietary plugin took 2 months to be available in Firefox after they rebranded hangouts as meet. and now it only supports SD video and crashes frequently.
instead of thinking of a solution that is cross platform and works on your walled-garden devices, you want to bring a walled-garden solution to your other platforms?