I fell out of love with the living wage when the UK government bumped minimum wage and called it living wage. The government kept on getting raked over the coals by charities who claimed that people working minimum wage were in poverty and so our govenrment bumped the minimum wage by a bit and then announced it as "This is the new NATIONAL LIVING WAGE". Which is just perfect politics. You're the government, so you can just take a term. Trump can brand the Gulf of America, and the UK Tories can just redefine the living wage. Now those charities are stuffed because any time they talk about a living wage everyone gets confused, it cuts the legs out of the conversation.
The core of the problem is that you basically have to have someone define what is an acceptable standard of living. Sharing a flat? Nah, the MIT trained economist thinks that's for the poverty people so that is defined as below living wage. Walk to work? No. You need atleast $10k a year on travel otherwise you're a bus wanker.
A huge amount of this is value judgements on what is an acceptable standard of living from people who benefit from immense privilege but will never experience the thing they're studying.