To build on top of Zhi’s answer, in most games PrePhysics is the performance bottleneck so we want things to happen later if possible. In most games camera movement does not affect physics so it is usually a good thing to run in parallel with physics.
Actor/Scene Components do not tick at all by default, so if you add ticking to a subclass you should set the tick group to whatever is appropriate for your game. By default AttachToComponent sets up a tick dependency so the child attaches to the parent, but you can remove that by calling RemoveTickPrerequisiteComponent if you do not want it. This dependency will only apply if the parent actually ticks, so if you attach a ticking thing to a SceneComponent that does not tick by default it will ignore the dependency. The automatic tick dependency setup does not always work well and many games override it manually.
I do not recommend changing the default in ActorComponent.cpp as that would modify many components you do not want to change.