The closest recent comparison I can think of is at COTA. Not a side by side situation but interesting none the less. Almost 15 seconds per lap difference favoring the F1 car.
Here's the story.
https://jalopnik.com/heres-how-indycars-lap-times-at-cota-compare-to-formula-1832587157
What ever the speed differences, the Indy car package these days make for much more interesting on track close quarters action. And the Indy series is including more road and street courses in their calendar these days too.
How ever fast the F1 cars are these days, I keep falling asleep during the parades, I mean races.
Cheers Richard