The Ortlieb Quick rack is working great on my gravel bike, feels like a quality product. I'm thinking of replacing the M6 mounting bolts on the thru axle with titanium ones then it won't be much heavier than the original thru axle.
Ortlieb Quick rack is a lightweight rack in general, but is only one part of a complete "luggage system". You get locked into a "pannier" system where you can fit their "my perspective" heavy panniers/bags, and perhaps a few other brands that can be adapted to fit their racks system.
When I write a "luggage system" I believe that you have to plan out what your gear requirements are for each adventure, and then pack accordingly.
Over the years, I have found that I personally don't like to bike camp for more than 2 weeks, and for many of my trips, they end up being 5 to 7 days. Therefore, I moved away from panniers, and started using ultralight dyneema dry bags. (2 to 4 oz total weight per bag, + a couple ounces more per drybag using Viole straps.) With this approach, I literally reduced my luggage base weight by almost 3 pounds!
Migrating away from panniers, or other "sewn and pre-fabricated bike bags/panniers" lets me shift my focus towards racks that properly hold drybags.
By moving to drybags, I select from 10L, 12L, and 20L bags that helps me limit how much gear I carry on a specific ride. This way, I can focus more on how much water and food I need to carry versus baseline gear and clothing. (One other evil these days, weight-wise, is all of the electronics one has to carry in order to navigate, communicate, and record one's adventures.)
I carry 3 to 5 pounds in navigation, cell phone/s, emergency beacon, back-up battery, lights and back-up navigation.Last thing to consider is that all of the companies selling racks and their associated bags/panniers/gear have to design their products to accommodate a wide range of applications, fit/adapt to various bicycles, and a wide range of consumer needs. Therefore, it is very difficult for them to optimize any one of their products and be able to sell enough of that product to stay in business. If you have fabrication skills, you can customize and tailor your rack and gear for your specific bike/s and rides, and this leads to a lot of weight savings and saves a lot of money overall.
As an example, in the rack image I posted earlier, I have a nice little tray area in the center of my rack. I was unhappy with where, and how, I was storing my bike tools and chargers/cables for my electronics, so I sewed up a nice bag that nests into the rack, and then I strap a drybag on top of the tool bag. This home made zippered bag weighs about 2 oz less then when I carried my tools in my "purchased expensive seat post bag", and the other bag I carried my chargers, spare derailleur battery and cables in.