Consumer phone market? iPhone was up against every single cheap phone that called and placed texts. Those phones are still popular for the majority of the population.
Enterprise market? Blackberry was king. Nobody else came close.
Gaming device? The DS and PSP were and still are powerful competitors. The DS in particular, because Nintendo's one of the king game makers and they restrict all their games to their own console.
The iPhone competed very effectively in all those markets. But it never had a risk of dominating a single one. Compare that to Windows — if I wanted a consumer operating system that ran the best/most popular programs, I had to get Windows, because there was no other operating system that had anything like the programs I'd actually have to use. (Mac OS? Not even close.)
If Google didn't have their huge amounts of cash, we'd still have the Blackberry OS, which is still enormously successful (though it's taken a hit recently), and we'd have Windows Phone 7, which is actually a really damn decent operating system.