The "things" of the real world are not "matter". They are color, sound, taste, touch, (as well as infinitely many others we cannot imagine).
This simple truth has been hidden from you and inverted to keep you from finding it.
Even now your programming is kicking in forcing you to want to laugh and reject the idea without giving it a single serious consideration.

But from those things any possible reality may be built, including all possible realities of matter, as well as infinitely many different _kinds_ of realities that don't behave like matter.
How could any theory be more robust than the very thing which tells you what reality you're living in in the first place? After all, the only reason you think you live in a world of "matter" is because you observe behaviors from which you infer it.

You have never once in your entire life observed matter.
You have only inferred matter from your real observations of color, sound, touch, etc.
These things cannot be defined within this reality because they are the axioms that create it.