What benefit can a worker gain from his toil?

What benefit do people get from all the effort which they expend on earth?

I realized that wisdom is preferable to folly, just as light is preferable to darkness:

If the snake should bite before it is charmed, the snake charmer is in trouble.

Yet when I reflected on everything I had accomplished and on all the effort that I had expended to accomplish it, I concluded: “All these achievements and possessions are ultimately profitless – like chasing the wind! There is nothing gained from them on earth.”

This is another misfortune: Just as he came, so will he go. What did he gain from toiling for the wind?