Many jobs require additional expenses: car, commute, babysitting, living in expensive city, no insurance for work related injuries...

So "not enough to live on" often means, it does not even pay job related expenses! Employees are subsidizing their employers!

My partner had a good job offer, but is at home! Buying extra car, petrol, child care... We would loose 150euro a month...

Just because the job doesn’t pay your expenses doesn’t mean someone else out there won’t take it and be happy they have it.