They’ve done that idiot thing they always do in these idiot articles and taken the average cost of a one-bed property in a certain area and done the maths on that, so the price is skewed due to all these luxury oligarch pads with concierge services and gyms, not places where regular people would live which will be considerably cheaper. Plus it ignores stuff like shared ownership that allows people to live relatively cheaply. The gf had a decent shared ownership in Zone 1 that she was able to get by herself with a salary of about thirty grand.
There’s a BBC article on more general house prices that appears every few months where they go ‘how much would you have to earn to buy a house’ in different areas of the country, again based on averages, but nobody starts out buying an average house do they? Most people start at the cheap end and work up as their family grows or earnings improve.