Nothing wrong with the age of an UI per se, but I think the notion of App's as silos which need to be individually opened get its information is rather old fashioned, and not ideal from an UX POV. Being able to quickly glance information from weather, email, social media does do quite a lot to lessen unnecessary UI excise.

I don't think it has anything to do with hardware, they can be engineered in such a way they don't needlessly drain the battery, nor do I think most people would feel it was useless. Then again, people sometimes don't miss something before they have it :)