Apple started a user experience trend many iOSes ago when it accepted Settings changes and did not ask for confirmation. Once the change was made, it was set. There was no canceling, accepting or double checking that the user wanted this.
In the controlled and consistent interface that is the iPhone, iPad and and iWhatever, this worked and even became understandable.
The problem arose when other platforms and standalone apps outside of the Apple ecosystem started accepting changes without asking me if I was sure about them.
There is a concept behind any user interaction in software that must be obeyed or these kinds of final decisions without confirmation can hurt rather than streamline the process. It is consistency across the platform.
Instead of trusting Facebook or other apps to make my changes without acknowledgement which allegedly saves me an extra interaction and click, I make the changes and then open the setting again to ensure it stuck.
I'm also stuck with the concern around whether I remembered what I had it set to before. If it is a toggle then that's not the end of the world but anything more than two choices and I sit there in despair hoping that there are no large consequences.
Although Apple has owned user interface designs since 1987 with the Macintosh Human Interface Guidelines, you are not all Apple. You do not control all behaviour in your world.
If you are going to make a change that sticks then make that so consistent that I will not doubt it or just do the decent thing and ask me for acknowledgement. You aren't saving me a click. You simply haven't earned my undying trust.