Incorrect Hypothesis

The fact that a single Theory of Everything is still sought demonstrates that the hypothesis is wrong. If it was right then there would be no conflict. Maybe things behave differently in different places naturally and we'd never realise anyway. Unless existence can happen simultaneously in two places, and being aware of both, it is an academic point.

Similar to the Heisenberg Uncertainty Principle: the position and the momentum of a subatomic particle, eg the electron. The precision of both cannot be measured at the same time with any accuracy. Detection and measurement depend on an understanding of what is sought.

Failure to achieve will result if the wrong tool is used.

The Unified Theory is speculation. It is reasonable since reality exists (apparently). Therefore such a situation as a Unified Theory already exists. The models that have been used in isolation 'seem' to work for some phenomena, but not others. The models are wrong. A single 'model' would provide a total solution if it were correct.

Keep searching though in the knowledge that nothing has been proven correct by virtue of no single theory having yet been discovered.

Other answers are equally possible if all dogma (and similar chains that keep everything 'inside the box') is ignored.

Denial And Skepticism