No. The human society would not collapse if there were fewer fishermen. The fact that the fishermen are so badly paid even if they work so hard, to me is a clear indication that the human society does not value their effort and it would be probably better if they would put their efforts into something else.

>>Is it possible wages often don’t reflect the value of the work people do?

I agree, there is often little correlation between the wage and the value of the work but the rational workers should optimize for the wage not for the value of the work if they don't want to be poor.