you know there a lot of possibilities to cheat . In game and in Life. It just depends on trust that you do not do it. Not everything can be technicaly prevented.

well, if an awesome pitboss mode was hardcoded into civ6, it could be done

It's no fun if you already know what the map looks like. Most people want to have fun, rather than wanting to win so badly that they will run through the entire game just to see the map.

yes, but there is a specific problem in multiplayer. You cannot know if your opponent is cheating or not.