refresh sram brakes or buy new

I'm not super particular about looks, but I do take care of my things. I bought a 5 year old fatbike that came with sram level brakes. Their performance and stopping power for me is just fine, but the levers and the calipers look like junk. It's mostly that all the bolts and hydraulic fittings have surface rust, though there are lots of paint chips on the levers (not pictured).

Is there a way to clean these up – or are there rebuild kits? Would you just buy replacements? Do other brands wear better over time? Maybe it's b/c this is the base model? I've just never experienced a component degrade like this.