Mutualism allows for other goals then just economic growth. Just as an example a housing cooperative tries to provide cheap housing for its members. If it has more housing, then that is actually a problem, as that has to be maintained as well. On the other hand the cooperative will built or buy more housing, if members housing needs are not already meet. That is very different from renting from some corporation and owning some of their shares. That is actually the case for a lot of mutual projects. Worker cooperatives might very well choose to not raise pay, but cut working hours. Utility cooperatives focus on providing the electricity, internet or whatever else for cheap and high quality rather then trying to make money.

In other words mutualism tries to meet peoples need, rather then grow for growth sake. Degrowth acknowledges that the economy has natural limits like for example greenhouse gas emissions, which should not be crossed. However within those limits growth is possible and even desirable when it improves peoples life's. The fact of the matter is that we need something better then capitalist corporations and mutualism certainly has some good answers to that problem.