@VikingOSX – agreed – the more folks submit feedback directly to the macOS product team the more likely Apple might be to listen to users on this huge UI Design screwup.
Personally I submitted it as a "bug" with the complaint "I'm reporting this as a bug because it has to be, I can't believe somebody in UI Design knowingly thought this was a good idea"
Not only does the save/open/print dialog box not "remember" the size/location from last use. But it's also difficult EVERY TIME because I have to perform TWO actions:
1) option left click the bottom right corner – which expands the box both horizontally and vertically at the same time – does not work unless you click in the EXACT right spot (which in itself is irritating as eff) and then...
2) I also have to make the finder sidebar wide enough to see which folder I need to navigate to.
Whomever thought this was a good idea needs their head examined.