If one is intent on brewing to style, what are the drawbacks to using a refractometer to determine when to conclude the mash (upon reaching pre-boil gravity) and likewise conclude the boil (upon reaching OG)? Seems like this practice would help to standardize the output and potentially save...

I am a relatively new brewer and have been using a Refractometer (BRIX) most recently. I have used the Northern Brewer calculator (https://www.northernbrewer.com/learn/resources/refractometer-calculator/) and the Brewer's Friend Refractometer...

I gather from what I've read that a refractometer is essentially a replacement for a hydrometer, right? Just an alternate method of measuring specific gravity? What would be the benefits/downsides of going refracto vs. a hydro (other than the obviously higher cost of the former)?