But my point is that noone has a robust system according to you in Europe at least - the bar is so high to cover all operating costs with fares (or is that your point - if so I'm lost - I definitely would not recommend replacing European transit networks with nothing?).

And National Rail isn't replaceable at all with bus/cars/planes. You really underestimate the number of people which commute >1hr into London (100km+). There is just no way to do that journey by car or bus. It would turn a ~1hr commute into a 3hr _each way_ and that's not even considering the complete lack of parking OR the fact suddenly the roads would be at (even more) gridlock with many multiples of commuters.

That's not even getting into what you consider fixed vs variable costs. Are the trains themselves a fixed cost (they should last 30-40 years)? Is track maintenance a fixed cost (this has to be done more often than the trains themselves), etc etc. The 2nd point is very important - a lot of rail operators in the UK can be made profitable or not on your metric by how much the government subsidises track maintenance vs the operators paying for it in track access charges.

Equally, are signalling upgrades (for example) fixed costs? But really they are only required to run more frequent services. So you could argue they are a variable cost?