I think the bigger question is more what kind of society do you want to live in?
One where 78 years olds are forced (yes some people work late in their 70ies and 80ies because they love it, I gather that it is unlikely that most Taxi Driver in that age range do it for pleasure) to work to live or one where 78 years old are retired, still participate in the society by joining non profit org, activities and enjoy their families?
HK is so backward on all of this. scrap fitness test and seek long term solution to improve the conditions elderly live in this so called world city.