On 6 May, 12:47, wrote:

The advantage of people paying by oyster isn't just reduced costs.
It's also faster journey times. It used to take forever for a long
queue to board a bus, when many people were paying cash. Now that
paying cash is significantly more expensive, hardly anyone does.

In a sense, having to effectively pay a penalty for using cash is the
price we pay for faster journey times. I don't think the people who
are responsibe for the difference between oyster and cash fares were
motivated by spite.

There is also the advantage of cutting down bus robberies. There is
less motive for villans to attack drivers to steal the money now that
there are often only small sums of cash in the box.