>>> "unemployment may be at an all time low"
Where are you getting your figures from, Theland? Even if we ignore two world wars and National Service (when unemployment figures were artificially low because so many men were in the armed forces), unemployment (expressed as the percentage of the available workforce without work) was far lower in the 1960s and early 1970s than it is today:
https://upload.wikimedia.org/wikipedia/commons/c/c4/United_Kingdom_unemployment_1881-2017.png
Regrettably though, there's no simple answer to your question about how to deal with 'shirkers and scroungers'. Attempts to do so (such as tightening up the tests for people claiming disability benefits) have a nasty habit of harming genuine claimants but leaving those who know how to 'play the system' totally unaffected.
Further, while the idea that such people should be 'forced to work' seems, on the face of it, to be a good one, it ignores the fact that no employer in their right mind is going to offer a job to someone who clearly has absolutely no interest in doing the job properly.
There are also 'borderline cases', such as people who are in receipt of benefits through some form of addiction. A neighbour of mine had an alcohol addiction, resulting in him receiving benefits. I met him coming out of the local JobCentre at 9.30am, stinking of whisky. (Who the hell would offer him a job in that condition?). As someone with an 'illness' it seemed perfectly right to me that he was getting support (especially as he had three kids) but, equally, knowing that he was making no attempt whatsoever to address his addiction, I felt annoyed that he was being allowed to 'scrounge' without limit. (That meeting was a long time ago. His kids have now grown up but he's still living off the state and clearly has no intention of doing otherwise).
As I've indicated in that example, the problem is complicated by the fact that cutting off a claimant's benefits can often harm perfectly innocent people (such as their children) who genuinely need help. So, while politicians (and newspaper editors) like to grasp at simplistic solutions, there isn't really an easy answer to the question you've posed. Perhaps if more people reported those who are blatantly fiddling the system to the authorities we might end up with fewer 'scroungers'?