Then you would have more rodents...
I've killed every snake I've seen on my property, as well as dozen of clients properties, and it's in the multiple of dozens every week during the later part of the summer.
During the fall and winter months, the field mice flock to any warm source.
I set the traps and clear them as needed. However, those clients I don't do their lawn care, have as many issues if not more than those I do their lawn maintenance.
So don't give me this BS that snakes will be beneficial to rodent control in every situation.