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.
There is nothing you can do to stop people from save-scuming all you can do is remove save so stop trying...
This does absolutely nothing againts save scuming. And is funny as hell.
You can still save scum to get the wanted result doesn't matter how the game gets to it. So hiding everything or dc or whatevere giving random fails whatever wont changes nothing.
If poeple are not happy with the result they will save scum. Some save scum just to see all the options... The only way to remove that is to remove save. Make them lose hours of gameplay... and even then people save scum or will just make mods.
btw:
IF RL DM does this and fudge rolls in nagative way just to fuck with the players you should find a new DM... i'm againts fudging all together, but ok i get it when it helps the players i can at least justify it a bit.
