Gasly and Albon endured disappointing respective spells alongside Max Verstappen.
The Frenchman was dropped in the middle of 2019, while Albon was replaced at the end of 2020 for Sergio Perez.
Both drivers struggled to contend with the tricky handling of the Red Bull, which seemed to suit Verstappen’s driving style more.
Horner conceded that Perez’s wealth of experience has given him a clear advantage over Gasly and Albon.
“I think the key thing in the appointment of Checo was his experience,” Horner said. “And it had been unfair, perhaps, on the previous two guys [Gasly and Albon] to bring them in so soon.
“I think Checo with that experience, he’s been through some of the hard knocks and so on with his career to that point, and I think what he’s brought to us is… he’s a very rounded guy, he’s a great team player.
“He’s got a good outlook on the development of the car and he’s very easy to work with, so that’s all the reasons for taking him in the first place, and he’s delivering on that.”
Looking ahead to the rest of F1 2023, Horner says Perez needs to be on his ‘A-game’ to contend with Verstappen.
“Look, Max is a hell of a competitor and he’s a tough… probably the highest benchmark in F1,” Horner added.
“But Checo is now in his third year in the team, he’s confident, he’s comfortable and he’s got to be on his A-game – not just with Max.
“[Ferrari’s] drivers are pushing each other hard, Mercedes’ drivers are [pushing each other] hard, we’ve got what looks like a pretty motivated veteran [Fernando Alonso] in a green car as well, so it’s going to be a really exciting year.”