London and some surrounding areas do provide more tax revenue than other areas of the UK but the more that is spent on infrastructure there the more attractive it makes the region and it just continues the cycle.
Although What you say is true we do have to be careful.
The most commonly used figures for transport spend per region are based on total transport spend where some or all of the investment come from the public purse. In doing so it means that schemes like Crossrail have the full spend allocated to the total, even though a significant percentage comes from local taxes or local investment (i.e. TfL spending money from its income).
To take this to the extreme to illustrate the point. If the Port of London Automatically spend £1 billion on port facilities but there is a £10,000 grant from a local council to include something that they want. Then as I understand it the current calculation would be for the full £1 billion. As such the perceived cost per person is hundreds of pounds (over the whole of London), yet the actual is measured in pence (for the local council tax payers).
As such the result would look like London was getting significantly more government money, when the reality is that all the investment is private or a small amount of local tax money. It then leads to the perception that London gets all the government money when the reality could be very different.
However there is another problem with that method, which is it doesn't count funding from private money if no public money is used. For instance if a house builder build a new link road to serve their development which provides a route around a town or releases capacity at a junction then that isn't included. Even though that may bring the biggest benefit to a region.
Even tgen any comparisons have to bear in mind the limitations of the calculation .