> For example, mutual aid networks
That in reality have never even come close to achieving much more then mutual aid. That such action could be wide ranging enough to replace the state is nothing more then fantasy.
The closest thing to that is Muslim Brotherhood doing aid, but that is with a clear component of military power as well.
> but even Friedrich Engels
Why would you say 'even'. Engles is not in any way shape or form qualified to make such statements. In his times non of these ideas had been tested. And said different things at different times for different people. Engels specifically publicly called out mass death would happen.
In the real world it has never happened and there is no indication that it would ever happen.