On the whole 'overkill' issue, can I just remind everyone that it's horses for courses.
Like everyone else here, I've seen it done 'wrong' many times - completely OTT PA, enough cabling to re-stage Live Aid, and the punters flocking to the smoker's shelter to escape the racket. So we've learned from that.
My bands go out with different-sized PA depending on the needs of the gig, we always have both backline AND PA support (kick drum only but we could add a couple of overheads if we needed them), plus we have @Silvia Bluejay out front with a tablet controlling the XR18. It ain't complicated, set-up from a standing start is always well under an hour, the amount of 'extra' kit is minimal.
Result? It's a commonplace for us to get compliments from the punters on how good we sound, both the balance and especially the sensible volumes at which we play. Sometimes Silvie gets tapped up by pub rockers in the audience, asking her if she'll do the sound for their band!
And of course we almost always get re-booked by the venue ...