Haskell could and would absolutely prevent this problem.

Haskell does not work by aggregating together the features that a whole system needs. It works by breaking down permissions per function. You would immediately see that a function which was only ever meant to do context lookups also has network access. This would be such a crazy type for such a simple function that no one would write it this way.

Don't think about it as aggregating effects, think about it as, all of the leaves of the system have the most narrow permissions possible. And that's where most bugs are, in the leaves.