Most macro photography enthusiasts will laugh at anyone using the built-in flash that comes with plenty of consumer-level cameras, with good reason, in most cases. I agree that if you are serious about macro photography then you should seriously consider buying a ring-ring flagship. The problem with these are is that they are expensive. For example, expect to pay around £250 for the Metz Mecablitz 15 MS-1 Digital Ring Flash. For a more professional level kit, you will need to pay between £500 and £1,000!
However, if you only take the occasional macro shot then there may be occasions when using your camera’s built-in flash to help improve your shots. It does depend on your model of
I think you will agree that the second image (with flash) is the better of the two. Both have had the same corrections applied for noise reduction and been tweaked for exposure levels. The first image, due to the lack of flash is much more noisy and I would argue, is less sharp, even though I had to use manual focussing for both images as I was using a manual lens with an adapter that doesn’t allow auto-focus.