I live in Southern California, with lots of hills and mountains and plenty of steep roads. They're all close or reasonably close to my home. Although a few pounds up or down won't make a difference in time, I prefer lighter weight over aero. Biking uphill is one of the reasons my heart rate is 42bpm as I'm typing this sentence.
I've got a 2017 Emonda SLR 6 (with a mechanical Ultra group set, including rim brakes). Even with lights and a water bottle cage, bike bag and computer, it's remarkably lightweight. I've added a lighter saddles and lighter wheel sets. Although I know I'd enjoy the latest and greatest, especially because I've rented such bikes, for now I can't see springing for a new ride.
Lately I've been biking to and walking up some obscure sets of stairs to strengthen my calves. It's not difficult to shoulder a bike that weighs 6.4kg.