Is this a track thing or is mercedes improving?
Maybe a little bit of both, along with the qualifying format switching things up.
A lot of times, teams blow through a ton of tires just trying to get to Q3, and since Red Bull has a solid pace advantage on most tracks, they almost always end up with a fresh set to use in Q3. The format they tested this weekend made it so teams didn't have to say, blow through their softs to make Q2/Q3 while others were using mediums or hards. It looks like that seriously might have introduced enough fukkery to mix things up.