Downvoted for speculating in a speculation thread, that's rich.
LMP1 cars back in 2016 had a weight of 875kg, dripping wet that was around 950kg. These new F1 cars dripping wet, are 885kg. These cars are so heavy that they drive more like LMP or GT cars than F1 cars, just from the sheer mass. When Vettel won his first championship the cars were 770kg with 150kg of fuel onboard. These new cars weigh more than that with no fuel in the car.
Then there's the tires, likely derived from the tires Pirelli provides for GT3 cars.