I see… obviously the same factors that make high levels of zoom easily achievable make very wide angles hard.
Yep, but the other point was Depth of Field, which is also influenced by field of view (which is influenced by the sensor/film size).
As I understand it, DOF is a product of the subject magnification and the aperture.
If you keep the aperture the same then moving closer to a subject or zooming in with a longer focal length means you get less DOF. Zooming out or moving further away gives greater DOF.
So… if you want to take a photo that is framed the same way on an APS-C sensor and on a 35mm film/sensor then you have two choices:
You can stay at the same distance to the subject and use a shorter focal length lens on the APS-C camera OR you can just move further away when you take the APS-C shot. Either way this means the APS-C shot will end up looking basically the same, but will have a greater DOF than the 35mm one.
That is also why compacts, which have even smaller sensors struggle to get a nice shallow Depth of Field, but conversely can do pretty well at macro-style close ups.