I can’t quite tell if Apple putting handy utilities (e.g. white noise) and options (e.g. reduce motion) within Accessibility settings, along with controls for braille readers and joystick controls, is part of a universal provision initiative (i.e. reducing stigma in having to use Accessibility settings).
My uneducated guess is that it’s done to avoid clutter for the rest of the settings and because accessibility is a good justification to outweigh this concern.