[Manuk]

Well mainly saving a game and reload does not make much of a difference due to the scale of choices you make in DOM. Consequences you pay in the current turn are of decitions made several turns ago.
And mainly you don´t loose a game just because you mismove 1 army. but saving last turn in backup could be useful for this cases of mismove or forgetting to give orders you already decided.

and for the save-reload mechanic or cheats like "research all" or "1 million bucks" are pointless and I don´t see why some people cheat. What point is to win a game that way?

If I cas Haruspex searching sites in a province and detects no sites I could reload and search elsewere. AI would not have a chance to this kind of cheating. Reload if a fire destroyed my lab. etc