I will say it without detours. The theory of everything will not come in the future. It has arrived in the past, precisely in 1865, with the following name.

A Dynamical Theory of the Electromagnetic Field

Impossible! That is a classical theory and does not cover quantum phenomena! Neither does it encompass gravitation, nor particles, nor strong and weak forces!

Actually it covers all that. And a little over 100 pages are enough to convince us.