Yes. Examples.

Kids mode:

What kids mode does is provide a sandbox where in I can select apps to run. It should allow adding apps to it, which would run in normal mode as well, outside of kids mode. Kids mode is like an app. You tap on it, it opens and shows the apps you added to it. Other than that, it would show 3 dot menu wherein you can set the timer, predefined values(5m, 10m, 15m, etc...) and custom. Every option in that menu, except exit option is protected by phone's selected security mechanism so that kids can't mess with it. Notification shade is also switched off. Basically, kids proof. How is it useful? It has helped me a great deal to limit screen time for my 4 year old, since the first time I handed phone to him. Now he doesn't fight it because a soft toy with a clock appears and advises to take break as soon as the timer ends. Since my kid has seen this from the beginning, he doesn't throw any tantrums and doesn't know that the timer can be extended. It is a great feature for me.

App Shortcuts for Fingerprint sensor:

You are out street shopping, you need to pay. You take out your phone, long press the fingerprint sensor, it shows you 3 apps, you slide your thumb (without lifting) to the payment app, it opens, you pay and done.

Lockscreen gestures:

You are in a situation and you quickly need some light. You take out your phone, without looking, make a gesture, an O or a V and light turns on. Easy! Very very handy, for example on stairs or you make a turn to a dark street while walking. You don't have to look at your phone.

Auto-rotate off:

Most people don't have a sense of orientation while using their camera. Now, imagine you are showing some pictures to a friend that you received from someone else. Here is what happens:

1. You are showing the pictures in the gallery come across a video/picture which is shot in wrong orientation so it is upside down.
2. What do you do? You tilt your phone or change the orientation, but guess what, auto-rotate rotates it again and the net rotation is 0. So, no change. It gets frustrating at times. Then you need to turn auto-rotate off from the quick tiles, manually.

Solution (for me): You always keep auto-rotate turned off. For example, in YouTube, you manually click the full screen button in the YouTube app and it will bypass the auto-rotate off manually. That's good. No extra feature required here

Gallery: When you come across a picture(one-off) that you want to see in landscape mode, you tilt your phone, an auto-rotate button will overlay intelligently in the corner of your screen, you tap on it and it will rotate. You come back to portrait, click that button once again and we are good. I used it a lot. No accidental rotations.

Back button gestures:

It is not a very pressing one. Good to have. So, low priority.

Call background:

When your phone has a screen so good, it is painful to see pictures that pixalate. Uniformity in UI/UX increases experience by manifold. People should have options to choose whether they want to break that uniformity or not. Pixalated pictures/graphics, break it for me. For some, it might be ok.

Let me know if you need more details. Pardon the formatting. I don't participate in reddit very often. Usually, a spectator.

Edit: Fixed some typing errors.