Lets see. 5 years ago, the best of the best mobile games probably had total profits of 300k.
Nowadays one of the bigger mobile games had revenue equivalent to a handheld game selling 500k but profits equivalent to a third party handheld selling 1million which recently has become far more uncommon then you seem to realize.
And this isn't even the biggest game. There are a few massive free to play and dollar games that are probably approaching if not exceeding 100mil in revenue and are more profitable than basically any recent handheld game without monster hunter or mario in the name.
The truth is the mobile market is accelerating at a MUCH MUCH faster pace than the handheld market. The only handheld games left that can exceed the bigger hits of the fairly new handheld market are mario and monster hunter. Remember nintendo giving out 1million free copies of zelda and nintendogs doesn't help them profit.
Big third companies are already porting a bunch of formerly handheld games to mobile devices. The line is rapidaly blurring to differentiate the devices. Big nintendo games will continue making more money than any mobile game for a while, but for third parties who not only need to pay shipping, packaging fees, and have retailers take a cut, also have nintendo taking a cut, mobile gaming is becoming a much more popular platform. Because selling 1million copies of a game at full price on a handheld is becoming very difficult.