$4.2 mil a year is a lot if you are still trying to live a regular, upper middle class lifestyle. regular 2 story home, 3 cars, etc.
But for a celebrity? That was once makin #1 hits on the hot 100 in his prime? Yeah, it's definitely ain't shyt for him. Like, dude was getting number 1's in the mid 2000s, and he was just 15-16, and not even fully a household name.
His fault for beating Rihanna though. Imagine if he didn't do that, and broke into the full-blown mainstream. The extra endorsements and features he would have gotten would have been crazy.