Gödel proved decades ago for all of mathematics including theoretical physics that a true ToE can't exist. The incompleteness theorem in a nutshell says no axiomatic system can prove everything about itself. There will always be truths of reality that can never be proven or reconciled with fancy maths, or detected with sensors, or discovered by smashing particles into base component fields. Really its a miracle we can know anything at all with mathematical proofs and logical deduction and experiment measurement. Its still possible we ca solve stuff like quantum gravity but no gaurentees.

Something you need to understand is that physicist types dont care about incompleteness or undecidability. They do not believe math is real. Even if its mathatically proven we cant know everything in formal axiomatic systems, theoretical physicist will go "but thats just about math, your confusing it with actual physical reality!" . They use math as a convinent tool for modeling and description, but absolutely tantrum at the idea that the description tools themselves are 'real' objects .

To people who work with particles, the idea that abstract concepts like complex numbers or Gödel's incompleteness theorems are just as "real" as a lepton when it comes to the machinery and operation mechanics of the universe is heresy. It implies nonphysical layers of reality where nonphysical abstractions actually exist, which is the concept scientific determinist hate most. The only real things to a scientific determinist is what can be observed and measured, the rest is invisible unicorns.

So yes its possible that there is no ToE or GUT because of incompleteness and undecidability, but physicist dont care and theres something alluring about the persuit.