Yes and No
There is no diffusion or scattering due to atmospheric particles in space, so yes, something many miles away will look sharp and crisp
when you focus on it. But depth of field still exists. DOF is a physical property of lenses (human eye included) which don’t alter.
If you were on the Moon, and took a photo at a low f-stop, like 1.8, the object you focussed on would look pin-sharp, but it would soon fall off into blur beyond it. The photos that came back from the Moon were taken with medium-format cameras with large lenses that allowed a very high f-stop, f-64, for example. At which point, almost everything out to infinity will be in focus. I’m grossly simplifying that, there are formulae which will determine the DOF for a given lens and f-stop that show just what distance things will be in focus for.
You almost never really notice DOF with the human eye lens, because it is constantly shifting focus to be on whatever you are looking at
And it‘s that property of the eye, along with the clarity of vacuum, that causes problems of judging scale and distance in space.
... and this is why it isn’t really going to be able to be implemented
It would look even more jarring to see a fixed DOF all the time, than one which altered depending on where your eye was focussing. So given the fact that we know everything in a vacuum will look crisp when you focus on it, it’s just easier to keep the idea of adjusting DOF out of rendering it, except in a camera view, Which is more realistic anyway, I think