London has exceptionally good public transport so you can live in social housing and/or ******** estates far out from the centre. You don't need a car and you never need to travel outside London because there is so much in London.
Renting a room in an apartment isn't that expensive, you can get rooms for under £10k a year. Minimum wage has been hiked up massively (over £10/hr now) and tax free threshold also hiked massively. So those retail jobs you refer to probably have a takehome pay that has risen a lot more in percentage terms than higher paid jobs have.
I guess if you accept renting for life it's not so bad. But isn't public transport quite expensive now?
Yeah I take the point about minimum wage rising. I was quite surprised how high it was. I can imagine it's starting the threaten some jobs "why should I do my old job when now any job pays the same".
Still sounds grim though. 10k a year for a room sounds super expensive to me. Especially on minimum wage.