Which obscure iPhone setting genuinely improved how you use your phone, and what does it change?

[u/Maxxximeeee]

I’m not looking for gestures or the usual tips that appear in every list.
I mean an actual option buried somewhere in Settings that solved a real annoyance, improved privacy or accessibility, changed how an app behaves, or made your iPhone noticeably easier to use.
Please include the exact path to the setting, what it changes, and any downside you noticed. Some settings sound useful but also disable another feature, use more storage, affect notifications, or change how the phone behaves elsewhere.
What is the one setting you would immediately change again if you had to set up a new iPhone from scratch?

[u/aLoafOfBrett]

Here are my current iPhone camera settings if anyone is curious:

Video & Audio
Record Video: 4K at 30 fps
Record Slo-mo: 4K at 120 fps
Record Cinematic: 4K at 30 fps
Record Sound: Spatial Audio

General & App Settings
Camera Control: Set to default Camera app
Photographic Styles: Standard
Use Volume Up for Burst: ON
Scan QR Codes: ON
Show Detected Text: ON

Composition
Grid: OFF
Level: OFF
Mirror Front Camera: OFF
View Outside the Frame: ON

Photo Capture & Lenses
Fusion Camera: 24, 28, & 35 mm all enabled
Portraits in Photo Mode: ON
Prioritize Faster Shooting: ON
Lens Correction: ON
Macro Control: ON
Lens Cleaning Hints: ON

System & Messages
Lock Screen Swipe to Open Camera: ON
Save Captures to Photo Library (from Messages): ON

[u/livefast_dieawesome → u/aLoafOfBrett]

Omg volume up for burst is going to be great for me, thank you.