There are already plenty of 1000-player games with 2000 objects that use a lot less bandwidth than this, usually because a lot of the object tracking is left to the clients while the server shares some form of player input. I'm not saying there's no possible reason to use 20mbps, just asking what it's for. Is the space game avoiding sending player inputs for anticheat reasons? How is the server updating the client on the objects' state?

I will say though, 20mbps of game bandwidth is different from video bandwidth. I'm guessing you require low latency too. And it'd be a lot for the clients to deal with, even the deserialization by itself.