One issue with fundamental theories that I've seen is that it's really easy to come up with a model that reproduces some aspects of relativity or even quantum mechanics, especially in some approximation, such as low energies or weak fields. In that regime, you can wave your hand and pretend that everything is linear or nearly so. The symmetries are common symmetries that a lot of algebras or geometries share, so things just "seem to work" almost magically.

This is like saying you've invented a car from scratch because you've made something with mirror symmetry that can roll forward. Obviously, this is missing more than a few details.

What Stephen Wolfram seems to have done is come up with an extremely generic system that can describe anything, in much the same way that a CAD program can use meshes to describe any piece of machinery you'd like to design. That doesn't mean that meshes are equivalent to metal and concrete. Just because meshes can have various symmetries and can be used to represent circular things doesn't mean that a mesh is a car either.

Similarly, in a very real sense the Universe performs computation, because -- duh -- it contains computers. And brains. And many things of that nature. Brains and computers run by the same rules of physics that stars and experimental particle beams do. Hence, the Universe computes. It also computes in the trivial sense that if you add 1 hydrogen atom to 1 hydrogen atom you get 2 hydrogen atoms.

So if you come up with a very generic form of computation, such as automata, or substitution rules, or whatever, of course you're going to find many things that "look like" various aspects of the computation the Universe is performing. But analogies are just that: comparisons of vaguely similar features. That doesn't mean they're isomorphic to each other, nor does it mean that some random theory is actually the rules the Universe follows.

Stephen spends a lot of his time jumping up and down and pointing at some trivial aspect of his theories and saying "Look at this! My theory can perform addition! The Universe does addition too! Hence my theory is the theory of the Universe!"

I've been interested in the fundamental theory of everything for two decades now, and I spend about an hour a day on average poking through random arXiv papers looking for ideas or signs of progress.

I've noticed a few things: Much of Wolfram's criticism of academia and modern theoretical physics is correct. It's much the same as Eric Weinstein's criticism. They both say that the politics and economics of academia make it nigh impossible to rock the boat and come up with radical new ideas. I noticed this too. Modern theoretical physics isn't. It's intellectual wankery and dick measuring as a way of getting pieces of paper and tenure. There's zero motivation or incentive to do anything useful, because the system has slowly evolved over time to disincentivize it.

However, this doesn't mean that their particular "rebel" flavour of TOE is correct, just because the models produced by Universities have gone nowhere. Progress in some arbitrary direction is not necessarily better than no progress at all! Progress in the right direction is needed.

Over the years (decades!) I've developed an acid test to quickly sort the wheat from the chaff:

1) Does the theory even mention particle generations? Bonus points if demonstrates at least three and explains why we haven't found four.

2) Is it a truly local theory in that global communication is never required? (Many current theories implicitly involve "solving" something, which is often implicitly a global minimisation.)

3) Can the theory be applied to single systems, or just ensembles? (Most QM theories automatically fail this one. Single particles exist, single electrons go into higher orbits from a single photon, etc... Either you can model this, or your theory is woefully incomplete)

4) Can it explain the observations of Quantum Mechanics without resorting to the "infinite dimensional" mathematical wizardry? Can it produce computable models, or just symbolic gibberish that I guarantee you no particle "computes" as it goes about its business.

5) Nobel prize winning stuff would explain the origins of constants that are currently experimentally determined inputs. (Most theories I've seen don't even have numbers.)

6) The ultimate requirement is for a TOE to "not only" produce the known observable physical behaviour but to also naturally exclude everything else. That is, the ideal rules should have some sort of incredibly tight self-consistency that can only happen in one way and can only produce physics. For example, an algebra that can only be used to represent valid combinations of particles and fields, and can never represent any other "invalid state" that makes no sense.

Unfortunately, 99% of the stuff I see fail at all of the above. Wolfram's theory does too. His current graph-based theory and his previous cellular automaton theory spectacularly fail the 6-th requirement. They're both nearly unconstrained computation models with infinite flexibility, the exact opposite of a good TOE.