I agree that granular fertilizer is better for turfgrass treatments in most situations. Particularly if you include a generous portion of slow release nitrogen. I have used a lot.
But I think a skid sprayer is better suited for weed control applications--particularly on large lawns. Over 8000 sqft. I think liquid herbicide application is superior in effectiveness compared to dry granule weed control, as most homeowers apply.
Except new "Lockup" herbicide may be far superior to conventional weed and feed products.
Of course, if you use granular weed and feed, but apply it more often than the liquid program, (and time it better), the results might be about equal. Suppose you applied weed and feed granular four times per year.
True, I hesitated to use a small spreader because it was lighter in weight, and looked similar to homeowner models. I wanted a big green one --even tho it weighed more--because that is what the big company used.