This is zero-evidence bullshit. On and after the age of 70, all UK drivers have to renew their licence every three years anyway - it's been like that since 1976. This new change just adds a requirement to get an eye test (which the government doesn't "make money" from) as well, rather than self-certifying.
Most of the price of petrol in the UK is government duty and VAT, then there is the extortionate road tax etc. The British exchequer rakes it in off motorists but fails to help provide safe and reliable alternatives.
The main problem I see with over-70s renewing their licence currently is that they have to self-certify that they are safe to drive. Many are reaching a position in which they rely on the car more and more because walking and going on the bus is harder when your agility, cognition and eyesight diminishes. Of course, they will self-certify that they are safe, that is perfectly understandable from their perspective. It needs to be independent.