Was feudalism beneficial to king

Feudalism indeed was beneficial to a king because he could tax his lords who were already taxing the peasants and serfs on his lands. He could further tax these serfs himself even more. In return he provided them with a stable country which could have been (or wasn't) relatively peaceful. It made sense for the king to stay in feudalism as he could gain a lot, simply by being in power.

Feudalism was beneficial to everyone because it was the method of you give me something, I'll give you something. The king had food from peasants and the peasants had shelter and protection from invaders