Personally I think that the universe would crumble without the Adobe Flash Player. Well, maybe not that drastic, but still. Practically everywhere on the web there's an Adobe Flash plugin somewhere. Even I've got a Flash object or two myself embedded in my site.
So why in the world do phones not support it fully yet? Like there should definitely be a built-in player for the Chrome that comes with an Android phone. Although, if I had to take a wild guess why flash is not supported by default for phones, I'd say that phone companies don't want to open up their phones to the constantly targeted security vulnerabilities in Flash. But who visits malicious sites with their phone anyway? Well I don't, so I'd like a Flash Player for my phone please! xD