Re numbers - the massive increase in numbers of applications for jobs does not reflect an increase in supply - it represents the increased ease and speed at which people can apply. This leads to distortion in both the expectation of employers and that kind of stat where 'nobody turns up for interview'
If you have 20 roles and 20 total competent applicants, each employer these days is likely to have 20 applications for each role, and shortlist the same 5 people, the first five to interview might offer to the same 2 leaving the third and fourth to start going down the list, the rest will be 'surprised' that the candidates they wanted don't turn up, or are no longer interested, so will go back to the pool and wonder again why the five they shortlist don't turn up to all the interviews.
Some down the list will go 'oh my god british workers are useless' and go to a polish agency who will fill from a queue. The market thinks there are no workers who turn up for interview, and only polish workers do, but in fact there were always 20 people to fill 20 positions.
If you are an applicant who is quite often by luck or just statistics in the 15 (the stats in that example, let alone the more realistic 100-200 applicants are that you are 75% likely with EACH APPLICATION to be not asked for interview, and not recruited, even though all of the applicants can do the job.
We have an application numbers issue,and a failure of businesses to understand it issue, not an ability or supply issue.
Ahem I hate to say it again, but with similar conditions, with my expert jiggery pokery and 4 years market analysis study, was able to treble appropriate recruitment two years ahead of a doubling target because I understand this in depth, and most companies, especially small ones don't/
You don't have to listen, as my previous bosses didn't, because 'who do I think I am? etc, but it is what it is.