You're no idiot.
You already know how to multi-task on iOS with the double-click on the home button. There should not be a multitask GUI created; that would negate the entire foundation of the GUI for touch screens.
If you want a larger touch screen buy one. Apple has them only in:
That might change, possibly with a larger iPad. The smallest 3.5" probably will get EOL-ed next year. We might get a wearable thing from Apple, though even though that probably has a touch screen I wouldn't want to put it in the category as we know it now.
As already posted, a 6 inch phone cannot possibly be in a phone category; the phone needs to be mobile, pocketable, small, in your (one) hand, in a small pocket. As mobile phones always have been - for a reason.