  A recent Letter by Zhu et al [Phys. Rev. Lett. 127, 247702 (2021)] claimed a
unified mechanism for quantum oscillations (QOs) in graphite-gated 2D devices
based on studies of three cases (WTe2, MoTe$_2$/WSe$_2$ heterobilayers and
bilayer graphene (BLG)). We find that not only are the claims of Zhu et al
based on insufficient evidence in all three cases but also critical aspects are
ignored. Their conclusions are hence unreliable.
