Yes, i know that but equally you could have some one working full time with a bad mental health condition who doesn't have the happiest or best time as well compared to somebody who is disabled but is happy in their life.
In terms of standard of living i mean money and availability and access to goods and services. I do believe and have repeatedly stated that everyone should have a basic standard of living; somewhere to live, food to eat, utilities, warmth, childhood education (i'm big on education and believe it changes lives), healthcare to a point- not elective plastic surgery/ turkey teeth etc, clothes, police/ safety, not to be locked up without commiting a crime. (There will be more than this which i've not listed). People working full time should be able to have more than that. Full time work should allow for more than the basics in life; holidays, cars, posh food, posh clothes, private health care, private education (obvs i believe in scholarships for talented kids whose family can't afford it).
People working full time should be able to see the point in that work and a difference to people on full time benefits. As is happening now some people can't see a difference, why work if you're financially very similar to someone who doesn't or only works part time?
The things that matter such as love, friendship etc aren't things which can be given or gained via benefits or work.