Some of the problems might come with the sort of material you are performing as much as the amount of amplification (I'm not a fan of loads of speakers and monitors in pubs)though I appreciate the need for adequate levels of amplification if the venue is noisy. We were in our local last Friday and the act was a 16 year old lad with a really nice voice. He did all the stuff that everyone expects to hear and the pub was really noisy during the 60 to 80s covers. Then he did a request- Bring Him Home, from Les Miserables and you could hear a pin drop. After that he interspersed the covers with some jazzy/ bluesy stuff and show songs that he clearly enjoyed doing and people actually listened. You will never get complete attention in a pub, its the nature of the place.

I agree totally with the comment on people learning to project their voices. My son actually does this very well and quite often chooses not to use a microphone in open mic. sessions (!, or where he has a listening audience. I know very few people these days who can do this.