Screws are not rivets. Both prevent the joint from working by establishing preload. Both prevent fastener fatigue by being under tension from that preload. Sure, the rivet also fully fills the hole to further prevent joint slip, but the screw and nut more than make up for it by being larger diameter, higher preload, and higher strength than the base size rivet.
Nothing to be concerned over. Bolted joints took over from rivets on structural steel many decades ago, and are used just fine in many things in airplanes, road vehicles, marine vehicles, and heavy equipment. The nice things about rivets is that they are cheap to buy, cheap to install, and you can know the joint is solid by visual inspection. If the rivet was a tight fit in the hole, the faying surfaces drew up tight, and the both heads pass a gage check, the joint is properly set and strong and can be confirmed as such also by inspection. To to the same thing with a much more expensive screw and bolt, you need a torque wrench and either detailed record keeping or Torque Seal and record keeping.
Billski