I think the MSE approach to budgeting would help many people.
It factors in birthday presents, car maintenance, boiler repairs etc and then breaks it down over 12 months.
It stops these things as being seen as a surprise cost. Some maintenance is inevitable, the problem is there's no way to know when it will come.
Many just work on the basis of regular bills and what's left over and then anything that deviates from that is a problem.
There will always be a proportion of people for whom saving is impossible as more goes out than comes in.
But there is another group where better financial management would really help.
The problem is that when you are in a rut and there's no chance of saving for the bigger things in life it is easier to be drawn into the small pick me ups of a takeaway or getting nails done. There's a huge amount of psychology at play too.