It already happened several times before with different players, so I wonder why they still don’t learn from it.
If a player is already offered around $20M per year or more, that is already a huge amount of money. At least before rejecting it, they should already know if there is another team willing to give them a better deal.
The problem is some players believe too much in what they think their value should be, without considering how the business side really works. Once the market changes and the offers disappear, regret comes in, and that kind of mistake is hard to undo.
Maybe they are confident that a team will offer them with a higher salary that their previous team are giving them. That's why they didn't sign in the first place. And it's obvious that they are looking for more money because they believed in their talent.
And they doesn't care about the business side of it. As they are thinking that team owners have a lot of money in the bag and they are willing to spend it to them. But there are exceptions and that there are players that really made that bad decision. Not over though for Kuminga, 2 years is good enough for him to show and proved that he is worth the money that he is asking.