The 16 limit is because the service is geared towards mobile, where 16mp is a bit extreme.
I guess the question is, what's the catch?
That you're trusting Google, for some. Others want higher than 16MP and maybe 4k video. Really, I'd be worried that they'd cut off the free unlimited at some point.
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Yep!
Well, sadly, you're wrong on that account. Apple has to follow the laws like anyone else.