After avoiding the turn one carnage at the Hungaroring, Mazepin retired after Raikkonen was mistakenly released from his pit bay into the path of the Haas driver.
With championship protagonists Verstappen and Hamilton dropping to the back of the field early on, Mick Schumacher went on to gain significant experience in doing battle with the Mercedes and Red Bull drivers.
That loss of experience for Mazepin is what Steiner finds most disappointing.
“For me, the biggest thing is Nikita missed another race where he could have learned a lot of things," Steiner explained.
"That is my bigger concern than the [missed] points at the moment. It happened, you cannot make it right and hopefully, we learn something out of that."
Mazepin points chance 'difficult' before Raikkonen clash
Steiner feels it would have been "difficult" for Mazepin to score points in the race even without his crash with Raikkonen.
Williams took advantage of the chaos that unfolded to score its first 10 points of the season - and first since the 2019 German Grand Prix - with Nicholas Latifi and George Russell finishing seventh and eighth.
Steiner feels such an outcome was unlikely for his team.
“They shouldn’t happen and maybe if you would have asked me immediately after the race I would have had some comments about it, what I think about how that happened.
"But for me, making points would have been difficult even without the crash."