Following on there has been a major new result in Quantum Foundations:
Quantum theory cannot consistently describe the use of itself | Nature Communications
In essence it says that you either have to accept:
(i) Collapse is a real process and thus measurements are special in some sense. There are physical systems that count as "observers" in some capacity
(ii) There is no collapse ever, just the illusion of collapse
(iii) Quantum Mechanics does not describe objective reality, just a single agent's expectations of experiments. Attempting to combine the predictions of different agents to construct an objective picture of what is going on is not possible.
(iv) Quantum Mechanics is wrong in certain situations involving macroscopic systems
Repeating my list above:
(a) Space is structured in such a way that the signal can pass without going faster than light, e.g. there are loads of mini-wormholes everywhere
(b) The signal moves faster than light (discussed above)
(c) Every time you make a measurement there are several worlds created
(d) The particles send signals not faster than light, but back in time
(e) There is no objective mechanical/mathematical/physical explanation of these coincidences between the particles values
(ii) leads to Many-Worlds or a nonlocal field [(b) or (c) in my list above]
(iv) is forced on (a) and (d)
As mentioned above, options (a)-(d) already have problems with fine tuning, so most physicists accept (e).
Thus this result forces them to take on either (i) or (iv). There are special physical systems that observe or Quantum Mechanics doesn't give an objective picture of reality, just what an agent should expect. In either case, the observer/agent cannot be removed.