One of the implicit parts of having an employer is that you're signing on for a certain degree of stability - you're both invested in the long term of the relat

One of the implicit parts of having an employer is that you're signing on for a certain degree of stability - you're both invested in the long term of the relationship. And that stability is reflected in your lower wage than a contract worker would exact for the same service. If that's not going to be the case, then trade offs that someone might make to invest in that long term relationship cease to make sense.