My understanding (and experimenting) is that PS always opens an image with "Fit on Screen" but not more than 100% zoom. So the initial zoom level varies depending on the pixel size of the image. I don't think that can be changed.
Someone asked this in Reddit 2 years ago. Amazingly (for Reddit) no responses.
I’ve been wondering the same thing. Photoshop always opening at 50% can be annoying when working with smaller assets. I don’t think there’s a built-in setting to set a default zoom, but maybe a script or action on open could force 200%?