Leclerc interview to Canal+:
We're just not fast enough. I'm frustrated because we had the same balance issues at T1-2 all weekend but we weren't able to fix it. We couldn't expect much more, and it's frustrating. I'm disappointed, but I guess it's like this.
The frustration is worse at Monza because we brought developments specifically for this track, and even that isn't enough to reach McLaren. There's still a lot of work for us to do, that's all there is to say.
His patented "it's like this" is back... both drivers look incredibly disappointed post-qualifying. Whether more was on the table or not, it's clear they
expected more.
I don't have the exact quote, but Sainz said in his interview that in order to make up for the issues in S1 he pushed more which killed his tires, hence his low S2/S3 times compared to Leclerc. Considering even he of all people was vocally annoyed by the understeer, it must have been stifling them a lot.
Fortunately, it shouldn't be as much of an issue in the race.