Is Everything Theory truth ?

I can prove that we can get what is named the Grand Unified Theory (GUT)
Is a model in particle physics in which at high energy, the three gauge interactions of the Standard Model
which define the electromagnetic, weak, and strong interactions or forces, are merged into one single force
But
We never will get what is named the everything theory (TOE ) when must addition the gravity energy
It means we can't merge the gravity energy with (electromagnetic, weak, and strong )
My question is :
If you agree with about what i have said , please write why ? by using your philosopical skils or rather your philosophical knowledge

Please accept the comment that answers your question.