CapnZapp
Legend
You really need to specify whether you're using feats, MC and/or items, Oofta.The rogue I ran in my last campaign did just fine for damage compared to the rest of the party so I personally don't see an issue. No, he didn't do nova rounds, but his overall DPR was close to other characters. At least close enough that it didn't seem to matter much. Rogues I've seen in play in other games seem to do quite well.
I can see that it could vary a lot. If you have only 2-3 encounters between long rests, never give your rogue a chance to hide to get advantage, always have the enemy assemble in fireball formation and so on it could make a big difference.
But I am confused - you complain that rogues don't do enough damage and then you want to limit their damage to once per round so that they can't take advantage of feats like sentinel? I suppose you also have an issue with rogues hiding and getting advantage while using Sharp Shooter feat?
Ultimately though I don't see a problem. If you want to do massive damage and go nova, play a different class. A rogue is more of a generalist who, in my experience, holds their own in combat. YMMV.
That's because if your experiences are in a no-options game we are actually in agreement!
I don't want to "limit" rogues - I want to "unleash" their potential two sneak attack damage for all the rogue players that can't or won't maximize. It's not that I don't understand that you gain twice the DPR if you use your reaction to sneak a second time. It's that it's uncharacteristically byzantine class design for 5E to rely on such a complex game feature. Did you read my suggestions?