Up here when I bought my old tourer in 90 or 91, another Japanese brand, (couldnt afford the Miyata 1000 at the time) it didn't come with a rack stock, but bought the Blackburn racks, best at the time. We have other bikes in the household with very similar aluminum rear racks to the Blackburn and yours, and they have worked great over the decades.
As TiHab said, keeping the rear load to a manageable amount is always going to be good for a rack anyway. It seems to me that at least one of our rear racks has a slight downward bend to the rear part also, with no ill effects--but again, they don't tend to get overloaded and ridden hard over rough surfaces--all that is to say that that rack certainly doesn't look in terrible shape, and has pretty minimal scrape marks on it from pannier hooks.
One of my bikes, an old 25 year old mtb I now use as my Canadian winter bike, still has its original rack, with quite significant wear, and I keep using it just to see how long it will last until it breaks!

While I'm a big supporter of using reasonable quality alu racks, Tubus racks are really well made and are stiffer and stronger than a reasonably priced alu one.

With any rack, especially with a heavier load, do make sure that the contact point of pannier and rack rail is not too "loose", ie lots of space that will allow the pannier attachment point to constantly bounce and rub against the rack rail. You can even just fatten the rail up a bit with tape, so less banging forces going into the rack, and also less rubbing going on, so less scuffing and wear on the paint and rail material.
Very easy to do and add more if needed--very simple and effective when riding on rougher surfaces.