This is really an argument against socialism as the communists tried to implement it. Where the state nationalizes every industry and all workers become employed by the state which plans everything centrally. Most socialists have moved beyond that model and would instead prefer to see a system of enterprise that uses co-op's instead of privately or publicly owned business. Some industries would probably be nationaliz…
The worker is also free to seek superior employment, if they feel their worth is not being fully appreciated / utilized (and so on and so forth).
Workers aren't appreciated at Business X? Start Business Z that treats its employees better. There are countless examples of this in practice over the last 150 years.
Unions are also properly legal under Capitalism. That is, the free assembly of labor. If employees don't like how they are being treated, they can collectively negotiate to try to acquire more leverage.
That completely removes your complaint about allocation of labor and accountability. Also, your entire premise rests on the notion that people are owed a particular job - just try telling nature it owes you shelter and three meals a day. The reality is, the capital to fund that job comes from someone that had to first create it. The West is losing this century because it has become lazy and hyper-entitled.