For zoysia and bermuda, yes. For St. Augustine, ESPECIALLY Floratam, not the case. Floratam just doesn't get that dense enough to choke out weeds. It needs to be cut higher, and as a result, reduces the amount of weed germination.
Good enough. I think we are on the same page for the most part. ST Augstine is just different but does not deserve the bad rap it often gets.