  In two-dimensional (2D) van der Waals (vdW) layered materials the application
of pressure often induces a giant lattice collapse, which can subsequently
drive an associated Mott transition. Here, we investigate room-temperature
layer-dependent insulator-metal transition (IMT) and probable spin-crossover
(SCO) in vdW magnet, FePS$_3$, under high-pressure using micro-Raman
scattering. Experimentally obtained spectra, in agreement with the computed
Raman modes, indicate evidence of IMT of FePS$_3$ started with a
thickness-dependent critical pressure ($P_c$) which reduces to 1.5 GPa in
trilayer flakes compared to 10.8 GPa for the bulk counterpart. Using a
phenomenological model, we argue that strong structural anisotropy in few-layer
flakes enhances the in-plane strain under applied pressure and is, therefore,
ultimately responsible for reducing the critical pressure for the IMT with
decreasing layer numbers. Reduction of the critical pressure for phase
transition in vdW magnets to 1-2 GPa marks the possibility of using
intercalated few-layers in the field-effect transistor device architecture, and
thereby, avoiding the conventional use of the diamond anvil cell (DAC).
