  Recently, Elouard and Lombard Latune [PRX Quantum 4, 020309 (2023)] claimed
to extend the laws of thermodynamics to "arbitrary quantum systems" valid "at
any scale" using "consistent" definitions allowing them to "recover known
results" from the literature. I show that their definitions are in conflict
with textbook thermodynamics and over- or underestimate the real entropy
production by orders of magnitude. The cause of this problem is traced back to
problematic definitions of entropy and temperature, the latter, for instance,
violates the zeroth law. It is pointed out that another framework presented in
PRX Quantum 2, 030202 (2021) does not suffer from these problems, while Elouard
and Lombard Latune falsely claim that it only provides a positive entropy
production for a smaller class of initial states. A simple way to unify both
approaches is also presented.
