Like @Peter says, powder coating can flake, that’s my experience too - but there are powder coaters who specialise in bike frames, and you’d expect them to be able to get better adhesion than a generalist. If the thought of a flake coming off at the dropouts doesn’t mortify you, powder coating is certainly cheap and much less work for you.
I prefer to paint my frames with a rattle can, and I have had really good results. Its more effort - you have to strip the frame or at least sand it smooth, then put on a couple of colour layers and preferably a clear-coat.
I have also tried the spray.bike paints, and they are very easy/cheap and give good results too. Here’s a Peugeot I did with automotive paint.
