At $600 that's a funny definition of "essential'...
For that money I can get a decent phone, a case, a tablet and still have change for a nice curry.
I find it bizarre that the price of top end smartphones has actually gone up, since they stopped improving rapidly 4-5 years ago. Completely at odds with how other tech goes.
I admit my £120 Microsoft Lumia 735 is totally rubbish for apps. If you need those, I'd spend up to double that to get a decent Android. I never got on with the iPhone, even though I like my iPad a lot. But I understand paying the Apple tax, if that's the ecosystem that suits you. But with Android you have a choice.