I used to think similar to the OP
A black coating would look terrible when marked and I believed they marked just by looking at them after reading the usual guff on forums. But I have to say modern coatings are more than up to the task of sustained rough use in my experience.
The SBS being the oldest black watch I own, is taking on a nice dark grey colour. With some burnishing on the edges it’s a nice look.
My tuna only has one minor scuff on the shroud, this was caused by me catching it on a wall. Even the aftermarket strapcode is unmarked bar the wear points on the clasp moving parts
The GMT is my holiday watch and gets beat to hell, it has a few pin pricks on the shroud but compared to the bezel insert, the shroud and case look almost new - this watch has been inside animals (it truly has), been in croc infested water, dug 4x4s out of rivers, all sorts (I am Bear Grills and I claim the £5) and there is no chipping, flaking etc just 1 or 2 pin prick marks. A new insert and it would look almost perfect.
The Synchron is totally un marked but it is only 18 months old.
That said paying a larger sum for a black watch and then marking it would drive me batty! That Seiko is lovely though, I was tempted.