Red Bull was hit with a 70% allowance of wind tunnel and CFD time as part of F1's Aerodynamic Testing Restrictions, a table which awards less development time the better a team performs in the constructors' championship.
As the reigning champion Red Bull therefore received the smallest allowance of all 10 teams, which comes on top of an additional restriction as a punishment for breaching the 2021 cost cap.
But despite its handicap, Red Bull has utterly crushed the competition in 2023, winning all eight races thus far as Max Verstappen cruises to his third consecutive world championship.
When asked if Red Bull's success means the effect of the ATR rules has been less dramatic than feared, Horner said the team would have been in real trouble if it hadn't had such a strong car from the start of the season.
"I would say the most significant thing is that we came into the year with a competitive car," Horner said in Austria.
"I think if we'd have been having to fix issues on the current car, then that would have been disastrous for us. Thankfully we had a good solid base."
Horner pointed out that Red Bull's in-season development did suffer from its restrictions, although he admitted the team has also been able to switch focus to next year's car quite quickly.
Source: Autosport