There are more than two billion mobile phones in use and nearly all of them can run a game. That is the largest installed base of any gaming platform ever assembled, by an order of magnitude, and the entire business built on top of it earns less than a couple of decent console titles.
The usual explanation is that the games are bad. They are, mostly, but that is a symptom.
Suppose you write something genuinely good for phones. To sell it you need to be on a carrier’s menu, because that menu is the only place a normal customer will ever look. Getting on it means negotiating with each operator individually, in each country, each with its own approval process, its own submission format, its own schedule, and its own opinion about what belongs there.
The operator then takes most of the money. Not a share, most of it. Figures of sixty and seventy percent are normal and nobody involved considers this remarkable.
Then there is the porting. A Java game is theoretically portable and practically is not, because every handset has a different screen size, a different keypad layout, a different amount of memory, and a different set of bugs in its virtual machine. Serious mobile publishers maintain hundreds of builds of the same title. That work is real, it is expensive, it produces nothing a player can perceive, and it has to be redone as new handsets appear.
Put those together and look at what kind of company survives. Not the one with the best idea. The one that can port cheaply and negotiate with fifty operators, which means a firm optimised for logistics and relationships, staffed accordingly. The structure selects for licensed tie-ins and puzzle clones because those are what such a firm is good at making.
Compare the DS. One hardware target. One binary. A shop with shelves, and a customer who can pick a box up and read the back of it. That is why a platform with a fraction of the reach produces the games people actually want.
None of this is a technical problem and none of it gets fixed by faster handsets. The phones are already capable enough. What is missing is a way for a developer to reach a customer without thirty intermediaries between them, and no operator will build that, because the intermediary position is the business.
My expectation is that phone gaming stays worth roughly nothing until somebody controls both the handset and the place you buy software for it, and can therefore ignore the carriers entirely. Whoever manages that will look like they invented mobile gaming. They will have invented a shop.