It's cool because it creates a relation between pure math (information) and physics (entropy).
Maxwell's Daemon is useful context. In short, it's a thought experiment about trying to "cheat" 2nd law of thermodynamics, and Landauer's Principle pops up as a computational speed limit of sorts.
> On the other hand, recent advances in non-equilibrium statistical physics have established that there is no a priori relationship between logical and thermodynamic reversibility.[19] It is possible that a physical process is logically reversible but thermodynamically irreversible. It is also possible that a physical process is logically irreversible but thermodynamically reversible. At best, the benefits of implementing a computation with a logically reversible system are nuanced.[20]