In the end, labour can "capitalise itself" by having all employees resign, form a body-shop company and apply to service the original employer. In an efficient market these two arrangements should produce the same outcome.
It is a matter of for whom is easier to organize. Capital can organize pretty easily, you may need only half a dozen companies to change a full labor market. But, you will need thousands or tens of thousands of individuals to achieve the same on the labor side.
So, you need laws to protect labor if they have to have any chance to organize themselves, or even to promote and finance such activities. Weak or non-existent labor laws creates a power imbalance in favor of capital. So, you only hear their side of the discussion.
e.g.: https://www.latimes.com/business/technology/la-fi-tn-tech-jo...
Capital is liquid, labor is not. Labor is emotional, gets sick, wants days off, doesn't want to work under undesirable conditions, etc. Capital doesn't have opinions, doesn't need to have elections and votes.