#3 is not about making observations in general but about making a map of every tree. This is a common mistake of scientists, wanting to have a complete set of data on their topic. I myself have to remind myself of this as well when designing projects. But in reality you cannot make a map of every tree and even if you could, what’s it worth? You need abstractions to understand anything and models are just that. To design a good research study you need to balance how many observations are necessary vs how much effort they take.
I feel like it’s just useful for different use cases. You don’t need to start with making a map of all trees everytime but it certainly would be handy if someone else had compiled a map of all / most trees for reference.
It just isn’t feasible. But maybe this is my ecological background speaking. Because, sure, if I’d look at different branches of science, it might be doable and also useful. But if you look at ecology (and making a map of every tree is ecology) then this just isn’t useful enough for a task that is basically impossible to achieve. That’s why in ecological research there are some standard sampling methods, like plots, transects, etc. Within these, you could do a map of all the trees if necessary. But these will be only a fraction of the whole system you look at.