As pikachuBob said, it would be a really nice feature but would mean a completely different landscape for multiplayer. Right now a single device hosts the farm while the other people join that computer. For cross platform there would have to be a dedicated centralized server system where all farms would be uploaded and hosted on a whim. It’s a massive undertaking and that’s not even including the insane amount of upkeep it would require.
Just to make sure it's clear, "crossplay" between Windows/Mac/Linux or between Steam and GOG is possible, but not between different consoles, or between console and computer.