Within the range limitations of the Shotgun/Choke/Load and the hunter's awareness of the limits of his equipment and abilities...buckshot will do the job.
As a hunter I have seen the results of both top notch performance and very poor performance with many types of firearms and loads...rifles, shotguns, muzzeloaders, and handguns. All are capable, within the limitations of the genre, of top field performance. All are subject to performance failures when stretched beyond design limitations.
There is however, more unknowing vitrol against the use of buckshot than any other ammunition type.