Silent Hill Townfall is yet another Unreal Engine 5 game with a bad HDR implementation.
On PS5 it does not support HDR at all.
On PC we only get the bare minimum. It's the standard UE5 HDR implementation enabled with a fixed 1000 nits peak brightness output.
PC gamers should, as always, use the RenoDX HDR mod for Unreal Engine in its extended version. It takes 10 seconds to install it using RHI (Reshade HDR Installer).
Why PS5 does not at least get the same HDR as on PC, I don't understand. It's still better than SDR.