It is not so much the shadows being cast as the amount of sun and ambient light and the % of sun included in the ambient light as Erich mentioned.
Also the material (or I should now say Surface) settings will have an impact.
For example here is the same material but with different Reflection > Ambient settings.
Other settings in the materials may also have an effect as well.
Barry.
One of the forum moderators.
Versions 6.5 to 27
i7-10700 @ 2.9Ghz, 32GB ram, GeForce RTX 2060 (6GB), Windows 10
Lenovo Thinkpad - i7-1270P 2.20 GHz, 32GB RAM, Nvidia T550, Windows 11