Why is there such a skill gap between standard AI and moderate AI

I always used to play against standard and while fun it was extremely easy, i have never had the land attack me and when i raid them they still have nearly all their resources.

So i switched to moderate AI and it was SOOO much harder, they rushed me befor the 15 minute mark and unless i wall myself of in dark forest i simply dont stand a chance with the stratagies i always used on standard.

Why is there such a gap? Playing 1v2 also isnt a great option because they still hardly ever do a full scale attack.