He didn’t phone it in, he never does. He went into this weekend knowing two things:
the Ferrari was likely to be faster over one lap due to the circuit’s mixture of long straights, big braking zones and slow corners suiting their car (see Monza).
the Red Bull usually has the best pace on race day regardless of its qualifying performance.
Gone are the days where Max has had to regularly risk crashing his car in quali to start as high up the grid as possible - he knows that as long as he has a strong qualifying and a clean start, he can almost always move forward in the race. His banker lap in Q3 was excellent and proved good enough to keep hold of P3 even as other drivers improved.
The only weekend this year where Max has really treated qualifying like life or death was at Monaco where your qualifying position is crucial because overtaking is almost impossible.