The pace difference doesn't explain this result. Verstappen was faster, yes — half a second per lap on average — but the gap came entirely from Sector 2, the high-speed middle sector where Red Bull has been untouchable all season. Russell matched him everywhere else. That's not a pace deficit you lose three positions over.
What does explain it: Russell pitted from the lead with no one forcing his hand, gave Verstappen twelve laps of free track position, and never got it back. The degradation data shows why: Russell's mediums were falling off at two seconds per lap by the end of his stint. Verstappen's? Less than a second per lap. He wasn't nursing tyres — he was controlling the race.