higher-level models are not just for efficiency (though they are mandatory for that: quantum mechanics is intractable to solve directly for even a carbon atom).

higher-level models are not just for efficiency (though they are mandatory for that: quantum mechanics is intractable to solve directly for even a carbon atom). They also are important for understanding. These two problems are much bigger in terms of applying the standard model for the purposes of 'explaining everything' than the problem of the edge cases it does not explain accurately even in principle.