One common objection to EA/utilitarianism is that it appears to demand a lot from us, and can end up in seemingly paradoxical situations. For example, why should we prioritise our own children over kids in other parts of the world? And if our work allows us to a lot of good, shouldn't we push ourselves really hard, to just below the point of where will burn out? One might reply that the total expected utility would be greater if everyone worked reasonable hours and looked after their own families, but this argument this seems a bit strenuous since it would require us to do an expected value calculation before we decide whether we should take care of ourselves or our families instead of working on our cause area. In my own life, I try to think of it as using different moral theories depending on the type and scale of problems that I am considering, something that is analagous to what we do in physics.
In physics it is often useful to know the scale of the problem before deciding on which theory to use. For example, say that we want to calculate the motion of a two-body interacting system. If the two bodies are fundamental particles, for example electrons, Quantum Electrodynamics (QED) would be best suited since it describes the strongest interaction at that physical scale. If instead we knew that the bodies are planets, consisting of an nearly infinite amount of particles, the gravitational force would be strongest and we should instead use General Relativity (GR). GR and QED are both equally valid at both scales - there is nothing stopping you from calculating the gravitational force between two electrons, but the result won't be very useful since the gravitational force is dwarfed by the electromagnetic. In a simplified way, we could draw the following diagram and use it to classify the different forces depending on which scale they are most useful:
Ultimately, most physicists believe that all forces are just different manifestations of the same fundamental force that can be described through a "theory of everything". Until such a theory is found, however, we are happy with using different laws at different scales, and someone specialising in GR wouldn't claim to know more about small scale interactions than someone specialising in QED.
Similarly, I think of the different moral theories as being applicable at different scales according to the following diagram:
Here are a few examples of where I think these moral theories are best applied:
a) Virtue ethics: Spending time with friends and family, self care. Following the virtues of "being a good friend" or "a good family member" seem to be more intuitive than doing an explicit calculation to show how this will lead to existential risk reduction.
b) Deontology/contractualism: Civil and human rights on a national/international level. It would be very strange to consider a society without the inalienable and individual rights to free expression, freedom of love, or fair trials, no matter the expected value in each individual case.
c) Utilitarianism: Future of humanity. On the global scale, aggregated over billions of lives, it makes sense to use utilitarianism to decide what to do based on a calculation of how many lives can be saved by different interventions, since any personal or national obligations can be averaged out on this scale.
The EA position is that we should focus more resources on trying to solve global scale problems, which I think is correct. However, as humans we also live in a local and national world, and we need moral theories to guide our actions in our daily lives. Just because utilitarianism is a great tool at the global scale, does not mean that it is the best theory at smaller scales as well. Ultimately, we will probably find a new "moral theory of everything" which works at every level, but until then we I think should see the competing moral theories as being useful over a certain range in space and time.