No, that's why he takes the risk, pays the employees the wage...

Taking the risk is paying the employees for their work?

Employees also take risks; they are the ones who will do the work, and thus at risk of accidents that in some cases end up taking even lives. Even if they are not harmed, the company closing or simply doing badly will harm the workers (who earn less than the owner of course) much more than the owner.

Owners have greater capital to diversify their sources of income and protect their investments; workers a lot of times work full time and still live in poverty, and you say the owner assumes a greater risk?

Tell me, when car factories close, who is it the one who risks poverty? General Motor's board of shareholders or the people in the assembly line?

Owners might "take risks" but its the workers who always end up paying the price.

Does the employee have to accept the job?

Well, he has to accept a job or otherwise starve.

What happens if there are no employers?

That people organise to meet their needs? AFAIK people baked bread and built houses long before these tasks were left to the market; it's only in the last 200 years that we've abandoned our social responsibilites and left everything for Capital to do and profit from.

In short, there's no need for the figure of the owner of capital when that task would be done more effectively by the workers who operate said capital.

Employers hold capital, which is necessary for society to function, hostage forcing people to agree to certain conditions in exchange for part of the product resulting of operating said capital with workforce (your salary). The owner here acts as a scalper, absorbing (the greater) part of the value produced through the capital he owns while the workers, who are the ones effectively creating said value, must agree first to give the greater part of it to the owner in exchange for a smaller compensation and the "opportunity" to work.