Exactly. But there are measurements/theories that indicate each possibility. So clearly there are some fundamental things that are not understood. The biggest IMO is "what is black matter?" One big problem is that, as humans, we only have a blip in time to measure movement.
If you take the current physics model of the atom and try to use it in the chem department, it doesn’t work. And vice versa. Both models have a lot of workability. But both ultimately are false.
In a universe as big as ours, some objects are coming at us in our direction and some are going away from us in the opposite direction.
Objects within galaxies would be doing both, as the spinning galaxy would have half it’s mass, figuratively speaking, coming at us and half spinning away from us.
Gravity Waves add another factor.
If a Gravity Wave passes between us and the object, Space would then expand and contract as the wave passes, which might take a million years. The Red Shift would then shrink then expand accordingly.
I think there is more we don’t know than what we do..........................