How the heck do you beat the AI?

I am convinced it isn’t even possible on harder difficulties, like hardest. Their building output is ridiculous, their army production and coordination is impossible for a human, their extra resources/faster build times break the game. And the computer does these moved simultaneously. Unless you’re playing islands or have at least 3 allies, I’m convinced it’s impossible to win. Even with F3 game pauses, my armies won’t build fast enough (plus they die very quickly). Plus the AI can move units in large spread out formations not even an option for the player. I like a challenge, but when there is no chance of winning at all, it just feels broken.