Why are LO zoom & font scaling different in Windows & Linux?

I’m curious what are the underlying issues which force LibreOffice to have different behavior on Linux and Windows regarding document zoom and scaling of embedded fonts. It must be some low-level OS difficulty. Anyway, can anyone point to a bug report or other discussion?

For example, document zoom settings are not preserved. The LO help text says as much: “Zooming is handled differently on Unix, Linux, and Windows platforms. A document saved with a 100% zoom factor in Windows is displayed at a larger zoom factor on Unix/Linux”

Also, embedded fonts don’t seem to be handled consistently, see LibreOffice Impress: Slides are formatted differently between Windows and Linux