My first AR (purchased in 97) came with a chrome BCG. At the time I had no idea what it was or why I needed it, it simply “looked cool”
Since then I’ve put thousands and thousands of rounds down range with that rifle and the carrier looks brand new (no wear marks like you see on plain BCG’s).
Its turned into my “beater” rifle, I run mostly wolf through it and it seems a little easier to clean than my other BCG’s. I don’t worry about scraping the finish from it when I’m chiseling out all the wonderful carbon cheap ammo seems to deposit on it.
I would say the average shooter will probubly never see an advantage from it but, if it’s a high volume rifle or if your lazy about carbon removal the extra $ for the chrome is a good investment.