Aliens wouldn’t need warp drives to take over an entire galaxy


According to this simulation, aliens wouldn’t need much time to colonize an entire galaxy. If that’s so, then how come the Milky Way hasn’t been settled by now? Or maybe it has.

Aliens Wouldn't Need Warp Drives to Take Over an Entire Galaxy, Simulation Suggests
It’s also further evidence that extraterrestrials should've settled the entire Milky Way by now. So where are they?