My 16 Pro Max’s battery life has been quite good this beta, but I am a digital minimalist in many ways. Always in Low Power Mode away from home, Airplane Mode always enabled unless I actively need to use my phone (except at home I leave just WiFi [calling] on), no keyboard haptics, Reduce Motion/Reduce Transparency/High Contrast/Cross-Fade Transitions quadruple-check…oh, and no Apple Intelligence or Siri/Suggestions/Dictation anything enabled. I have Siri & Apple Intelligence as well as Search toggles fully disabled for every possible app and Background App Refresh is switched to WiFi-only.
iCloud backup via cellular off, WiFi Assist off, all analytics disabled (yeah, yeah, sorry ‘bout it [not really]), “Help Apple Improve Search” obviously disabled, and Enhanced Visual Search off in Photos.
I also don’t use the always-on display or StandBy, for what it may be worth, and I try to keep all third-party apps off my device—preferring to use websites in Safari instead—unless they have a clear non-collection privacy label in the App Store. Speaking of Safari, I use Wipr 2 (still in beta but releasing first half of November I believe) as my content blocker of choice—it is absolutely excellent.
And, finally, here are my Location Services pages if anyone happens to be curious. Maps routing and anything else I normally use works just fine with this configuration. “Product Improvement” toggles are switched off in System Services.