A lot of people only tend to look at the fuel costs and maybe parking. However you're forgetting a big part of the costs of driving which is that every km adds to the depreciation in the cars worth as well as requiring more maintenance.
It's very easy to say just buying fuel is pretty cheap, but those costs are easily doubled if you look at the full costs. Check out https://www.anwb.nl/auto/autokosten for examples of how much variable costs/km actually are.
That said, this is for solo travelers... It's true that when you add more people the costs become much lower / person if you go by car since the costs just get multiplied with public transport. Exactly why my next vacation with 4 people will still be by car...
However I've started taking the train for work now which still comes out a lot lower (40% discount outside of rush hours helps a lot too!)
No yeah agreed I wish they'd make it cheaper too.