Well it depends what exactly the issue is when you call it dull. Compound polish works well when you have mini scratches and swirl marks from washing. A compound would actually take off a bit of the clear coat layer (which is transparent) and then seal it again with a polish.
However, a less abrasive version you could try would be to claybar that might work. Try touching the paintwork after a wash and see if the car feels smooth, if it doesn't I'd recommend you to get a claybar and maybe look up how to use it. Should take you an hour to do it yourself and afterwards if you polish the car you should have a longer lasting shine. There's microscopic particles that bond on the paint that you are trying to remove using the claybar, so that might restore the paint you are talking about
