Multiples like P/E are just a proxy for cash flows, discount rate, and growth. That P/E tends to stratify on industries makes sense not just because of growth,

Multiples like P/E are just a proxy for cash flows, discount rate, and growth. That P/E tends to stratify on industries makes sense not just because of growth, but also its sensitivity to capital structure. So asset heavy companies with lots of leverage will have different P/E ratios even with the same unlevered free cash flows.