2MB or similarly large pages are problematic because of fragmentation (lack of contignous free memory) caused by smaller pages. You either get them easily during startup or risk having problems allocating them later. And smaprthpones/tablets don't get rebooted, they stay on. 64kB is much better size in this regards. 64kB is also a candidate to fully replace 4kB pages, while 2MB is not.

16kB would of course beat it for swapability, but the size of Flash pages increases constantly, so perhaps some day they would match.