Why celebrities get paid so much compared to normal people?

I was looking at the pay for one peace live action and some websites mentioned a pay over 150k per episode per actor 😱

I understand that you give up your privacy, and jobs in creative fields are not very common..
However, the difference compared to an average worker is crazy. Here in London, the average yearly salary is around 50k!

Just to clarify, I’m not comparing actors to nurses, mechanics or hard labour workers, just in general to the rest of us from a financial prospective.