The thermodynamic "limit" is pretty small compared to any other waste in a system (from Wikipedia):

> At room temperature, the Landauer limit represents an energy of approximately 0.018 eV (2.9×10^−21 J). Modern computers use about a billion times as much energy per operation.

The Landauer principle gives a lower bound for the energy needed for computation (specifically, irreversible information erasure). Is it possible that there is a heretofore undiscovered lower bound that is higher?

As an aside, modern computers perform computation like a car with square wheels --- in discrete steps, where all your energy is irreversibly discarded in each step. Theoretically, reversible computing [1] can do useful work with less energy without needing to erase information.

[1] https://en.wikipedia.org/wiki/Reversible_computing