Because in a better world, the "top salary" would go to those doing "something groudbreaking". As it is, the pay structures in society are totally inverted compared to social value they provide. In particular, the system is set up to give highest rewards to those who work on scamming other people.

No approach will ever make everyone happy, but some people would be happy with those deals. It's only natural to want to work on interesting problems and be paid well & I don't think there's anything wrong with striving for that. In an ideal world we'd only work on what is the most interesting to us with no concern for money. In the real world there is an unfortunate flaw where we need money in order to survive. Lots of companies have an even worse issue when trying to recruit where the work is boring and the pay is average.

i think you mean, there will always be at least one person who is unhappy.