Boundary lubrication is a deep topic... The short answer is that lubrication often works better when the lubricant can chemically adhere to the surfaces. That means the surface energy needs to be high enough to adsorb lubricant. Low friction smooth dry surfaces typically have low surface energy.
Here are a few random links to get you started...
https://www.sciencedirect.com/topics...ry-lubrication
https://www.researchgate.net/publica...Concentrations
https://pubs.acs.org/doi/10.1021/acs.langmuir.1c01581
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