For most people, the “better” everyday flagship is the one that fits their existing ecosystem and preferences. Choose the iPhone 17 if you already use Apple services/devices or strongly value simple cross-device integration and resale. Choose the Galaxy S26 if you want more customization, Android flexibility and Samsung’s feature set.
For camera use, compare the situations you actually shoot: children/pets, indoor photos, zoom, selfies and video. For battery, focus on your network and app mix rather than headline endurance numbers.
If you are starting from zero with no ecosystem preference, compare total ownership cost: storage tier, charger/accessories, repair prices and trade-in value. Those costs can make a bigger difference over three or four years than a small performance lead.