Capital mobility across industries and equalization of profit rates
This is a massive area of research, revived recently under the title of "capital misallocation".

Some reason why capital do not fully adjust:


grow in intangible capital-intensive sectors (which require more internal financing than other sectors) + low interest rates.
quadratic adjustment costs on investment.
financial frictions lowers access to credit to small yet highly productive firms.
industry-specific physical and human capital.


The are many more papers studying financial frictions and related aspects of the financial market, showing that the role of finance is very important.