The scenario involves a 1v1 Arabia match where the opponent chooses to play with Cumans.
During the Feudal Age, you launch a raid attack, but the opponent is quick to build a market and establish a 2nd Town Center on wood and stone.
Eventually, they also build a defensive castle, and their knights push you back, followed by another castle.
The game turns into an Imperial Age trebuchet war, with the enemy investing a lot to defend their trebs and castles.
They destroy your castle(s), walls, and siege at the cost of their military.
However, their castles are still up next to critical resources like gold and stone, and your options are limited.
Hence, you consider strategies like researching Chemistry for Bombard Cannons (if your civ allows), deploying Capped/Siege Ram with Pikes/Halbs, or expanding outward to new woodlines for lategame trash unit spam.