It's a tradeoff - people slimmer model phones with less room for batteries, want their phones to be super powerful and run all kinds of apps, then demand longer times between charging their phones. You can always disable the battery saving features and get more/extra batteries or battery packs.
To disable Doze for an app: Step 2: Tap "Battery" from the Settings list and then hit "Battery optimization" option from the top-right menu icon. Step 3: Select "All apps" from the options to bring the list all the apps on which doze mode is enabled. To disable Doze for specific apps, open the Settings app and select Battery.