The things we think of as "observers" are extremely complex - so we're proposing something very restrictive, when we propose that we might understand physics. We're saying that there are no artifacts of this relationship that blind us.

It's important to be aware of the known mechanics of electrons; they don't move at all like classical objects; but it is their motion from which classical motion emerges, in some sense, too

It is almost arbitrary, whether you discuss things as a space populated with stuff, or if you just discuss the stuff and its relationships with itself; the nature of space is one of unreality.