Why did medieval merchants, like artisans, peasants and feudal lords, create their own associations?

I can assume that such associations of people of the same profession were created with the aim of supporting each other. In addition, if the entire association came out with its demands, this forced the authorities to listen to the opinion of its members and make certain concessions.

It is worth noting that the members of the association, say, merchants, could easily agree with each other at what price to sell this or that product.

In addition, the members of the associations could also negotiate material assistance to their comrades in a difficult economic situation.