My two cents
The stakeholder map and ecosystem map are not tools that l I use so often. Nevertheless, to me there are useful whenever I feel I need to better understand the context I'm working in.
Don't make them alone
Instead of making such stakeholders maps or ecosystems alone, I prefer to ask people to draw them for me. And then I can see what are the different understandings of the situation that exist within the same organization.
When to use them
If you work on very complex projects, that can be something that can be useful to understand the complexity of the, ecosystem you're working with.
When not to use them
But I work usually on problems which are simple enough that these types of tools are not so helpful.
If we take the example of trying to improve the waiting time of a cafe, making a stakeholder map or ecosystem map will not help you so much. It might even create more chaos in your head.
A good rule of thumb
When you use mapping tools the question always is:
Will more information help me better do my job?
Sometimes the answer is yes, and sometimes the answer is no.