The idea of hiding DCs for skill checks did get me thinking, but on reflection I’m not sure it would stop me reloading if I were tempted to, just make it more frustrating as I wouldn’t know how close I was getting. But clearly mileage on this will vary and I can see it might feel less like failure if you just roll and something happens without it being clear whether your roll beat the DC. If DCs were hidden I wouldn’t object, and if it were an option toggle then I do think I’d give it a try.
If the goal is to avoid save-scumming and reloading to get only successful rolls, then it is not sufficient to only hide the DC. You need to hide the DC, and ALSO make it so that succeeding the roll can be the "bad" option, while failing the roll can be the "good" option, say, 15-25% of the time. Then you are motivated to accept whatever result you get if playing blind, as you do not know when rolling if winning or losing is what you want. Real-life DMs take this into account.
