Both sides were missing a host of players as the match fell outside the international window, but the Springboks ran in 11 tries and pushed Wales backwards in the scrums in an utterly dominant display.
"Obviously it’s disappointing, the scoreboard," Tandy told reporters. "We were up against a world class team who dominated thoroughly. It’s the learnings of how far we need to grow. It’s reflections.
"It can’t take away from the buildings of the first three games (in November). We need Test matches.
"It’s always hard to watch when it’s hard to get any grip of the game. Penalty count goes against you and it’s hard to get a grip.
"The margin, it stings. It’s really raw for the group. It’s not for the want of trying."
Springbok coach Rassie Erasmus was a player when they beat Wales 96-13 in 1998, and has now been involved in their number one and two heaviest defeats in Wales' history.
"I think in those days, we didn’t have much of a gameplan. I thought today was a really controlled performance. We’ve been building up and building up," Erasmus told reporters.
"For me, it was probably one of our most clinical performances. I think Wales are in between what they really want to do. It will come right.
"If they can get players fit and get caps into them. It’s a difficult thing to get out of, losing that many games. You’ve got the support and the players have the fight.
"In 2016 we were nowhere. In 2019 we won the World Cup. Anything’s possible."
South Africa's night was soured by a red card for lock Eben Etzebeth for an apparent eye-gouge on Wales' Alex Mann.
"I don’t know what I can say that won’t be controversial," Erasmus said of the incident. "It didn’t look good. It justified the red card. How it happened and why it happened, whether it was provoked, I’m not sure."