Truss

Is to promise great prospects or deeds and not fulfilling them after a couple of days and abandon them completely.

"John really truss things up on the project"

"Yeah he can't even last a couple of days"

"At least we still have you Mr. Lettuce"

Rich kid

A rich kid is child that have parents in the middle class and beyond. Usually, a rich kid got things he wants in life and extra for pleasure. Not to be confused with spoiled rich kid, a rich kid could be humble and gentle with others or even good with money if his parents pass down their knowledge of money to him. In addition, he could be grateful on what his parents give to him.

Rich kid: I am happy that I got the PS5 on day one!

Regular kid: Lucky

Another example:
The rich kid manage to get the newest console on the day of release.