2019 Kubica is also a good candidate. The car being dogshit and both drivers regularly staying on the back of the grid masks it a bit (eg. 18th vs 20th) doesn't sound like a huge beating, but if you factor in the actual laptimes, race pace and all it's devastating. Yesterday neither Russell or Kubica had notable issues with the car. Russell started from the pits, Kubica started on the grid. Russell ended up 18th in front of a Haas. Kubica ended up 20th, lapped by Russell. With Gasly you have the partial justification of getting lapped that he stayed a lot behind the McLarens (to his own fault, mind, but obviously it meant he couldn't do his own pace). Kubica had nobody around him, and yet he managed to get lapped by his teammate. It's unreal, and it's not even an isolated incident.
In Australia, Kubica's qualifying lap was 1.7 slower than his teammate's. Pretty close (still behind) in the next two Saturdays, then 4 tenths in Baku, 1.2 seconds in Spain, 3 tenths in Monaco, almost 8 tenths in Canada, over 4 tenths in France and 3 tenths the other day. His race pace is nowhere near Russell's (who's a rookie, small reminder) on Sunday and he yet has to beat the guy in qualifying, getting quite the beatings there as well.
Verstappen destroying Gasly seems more obvious because there's more cars inbetween them, but in terms of raw pace Gasly isn't that bad.