I agree that Black is more on the defensive, in terms of structure. Once white gets his pawn to c4 he can put on a sort of central clamp, where Black has to be careful about moving his pawns, or he might allow White to get a passed pawn rolling down the center, or possibly invade with his pieces.
Though there are also other pieces in play, too - which expands the possibilities for Black.
I found a game between Redfish (a modified version of Stockfish) against LCZero (with the Black pieces). LCZero went into that e6+c6 pawn structure, and looked like it got pushed back on its heels.
But Black managed to find enough resources to hold (some impressive moves in there - look at 30... Ne5!).
I believe the Scandinavian is sound - but Black has the harder game, and likely will have to find some creative moves along the way.
The Scandinavian actually holds, even at the engine level (with Stockfish vs. LC0, for example, it's generally a draw).
A lot of players think, "Nc3 and White wins a tempo on the Black queen! Hah!"
But chess is more complex than that.
For starters, the knight isn't ideally placed on c3, where it blocks the useful c-pawn. White would much rather have his pawns on c4 and d4, side by side, where they fight for the most central space - instead of having a lone d-pawn in the center and his c-pawn stuck on its home square, not participating in the game.
This gives Black the luxury of placing a bind on the d5 square (with pawns on c6 and e6, for example, in the future). If White ever wants to fight for control of the d5 square, he'll have to move his c3 knight again, to give his c-pawn room to advance - thus admitting that his knight was misplaced in the first place, and thus "returning the tempo" ...
Chess is complicated.
The "tempo" was never the reason I thought the Scandi was bad, it was always the pawn structures afterwards.