I certainly think one aspect of tap in tap out contactless PAYG is it completely stops you thinking about what the fare is. Which is only bringing it into line with cars, where because you just put fuel in periodically you tend not to think of the cost of an individual journey, just roughly how much you spend on fuel each month.
But this is not necessarily the case because you only don’t think about what fare you will be pay for the duration of the journey. As soon as people tap out they see the charge for their specific journey on the barrier and on their online account. In a car you don’t see the journey cost on the dashboard as you get out and this only applies to a taxi.
People often don’t realise fares vary throughout the day. They just tap in blissfully unaware of how much they will be charged and jump out of their skin in horror later on. Then they end up on here looking for answers. Tapping a card doesn’t feel like spending money.
When it comes to the car, people have a rough understanding of their cost per mile of fuel and can estimate their journey price based on distance. Driving a 15 mile journey at 6am costs the same at 1pm. You can leave whenever and pay the same. Trains are a completely different kettle of fish.
A rail journey of the same length at 6am could cost £8 while at 1pm only £3.50. Unless the railway moves to a fixed distance model, this won’t change. When using using as you go, unless you look up your fare before travel there is no telling how much you will pay. Even with London’s zonal fares system it gets confusing. Buying a ticket upfront is the only way of avoiding this.
In your example, filling up the car with £5,000 of fuel each year and traveling to and from work (same place and distance) would be akin to topping up a smart card of the same amount and travelling between the same 2 stations at the same times of day.