I do have a Mac with an Intel processor, even with an i7 core just as mentioned in the game requirements. So the problem would be that my graphics are also Intel?
That is exactly the issue, I'm afraid!
As mentioned above, support for openGL was removed in recent patches for this game and Vic3, which means they will no longer run on that unsupported hardware.
All you can do is revert to the previous 1.10.2 version in the Steam betas tab, or play on some other machine that meets the hardware specs. Also, if you have Apple Bootcamp installed it will probably work there.