That is just a bald assertion. Come back when you can demonstrate that there is a third option.
EDIT: Or (epistemically) a second.
That is simple. It has to do with the 3 versions of wrong.
It is wrong, that I can fly in earth gravity solely by the use of my body. (P as physics)
It is wrong, that in base 10 that 1+1=10. (C as cognitive)
It is wrong to kill another human. (M as moral)
Now if everything is one category you have to be able to reduce P, C AND(logical strong and) M down to one or alternatively prove P, C AND M.
So what is involved in the 3 categories: Observation, cognition and feelings.
Now we test if you can observe everything. No, because you can't observe a feeling. You feel it, don't observe.
Now we test if you can think everything. No, because you can't think an observation. You observe, don't think.
Now we test if you can feeling everything. No, because you can't feel an thought. You think, don't feel.
So now to logic. Something can't at the same time and place and in a sense be and not be in that sense.
So for P, C AND M they can't be made logical consistent because the different senses of P, C and M can't be made into one.
I.e. you can't do everything humans do, only doing one of the categories and there is no one way to say what everything is in one sense.
The third option is that we can't do everything so that it adds up and makes sense. In naturalistic terms as per biological evolution we are evolved to live in the world and that doesn't require that we can make sense of everything.
Some religious people believe they can make sense of everything using God. They can't.
Some non-religious people believe they can make sense of everything using science. They can't.
Some people know there is a limit to both religion and science in terms of making sense of everything. They are called skeptics.
So you are a believer in that everything is physical. It is not, because it is too simple, just as God is too simple.