Part of the problem is how much wider on average cars have got, making it less viable to park next to the curb or with just 2 wheels on it. Another part is that both members of a couple are more likely to be working and needing separate cars, and if their kids can't afford to move away, than that's an extra car too. Additionally, councils have convinced themselves that not lowering carbs to allow for extra driveways is promoting public transport use, ignoring how unviable that often is.
Cars with all 4 wheels on the pavement annoy me, but it's become so normalised that drivers have looked at me, like me walking on the pavement is an irritating obstruction to where they have every right to be. I think the police in some areas allow you to upload a photo to report them, but it's not something I'd do 'cos it's a complex problem and fines aren't the solution.