The Guardian article says that applicants for low skilled jobs have reduces for 24 to 20 per job and for medium skilled jobs from 19 to 10
This has meant that companies are having to increase salaries to attract the right candidate which can only be a good thing. It's not saying there is a skills shortage only that there is less of a glut of people applying for the same jobs
This is exactly what I wanted Brexit to do. All good as far as I'm concerned
A company employing low-skilled workers still has 20 applicants for each job, so only a fall of 16%. By definition, low-skilled jobs can be filled by low-skilled workers fairly quickly (as there is little training time needed) so these companies will not be greatly affected.
A fall of 47% in the availability of medium-skilled workers however presents a greater challenge. Companies can pay higher wages, which in turn causes higher prices, making products less competitive. If a combination of increased costs and unavailability of labour means that a company cannot continue, it will either close or relocate. My own company has already relocated to the EU as 1) that is where 90% of our clients are; 2) we have no idea about what barriers to trade we would have faced post-Brexit and 3) most of our staff from the EU (whose language skills, market knowledge and contacts we require) have returned to their home countries.
As for the availability of applicants after Brexit, there is a completely different model that might come into play which absolutely won't be good news. Suppose British manufacturing collapses (as even Brexiters are predicting) then as many as a million skilled workers will lose their jobs, as well as all of the other workers whose jobs depend on the spending power of the now-unemployed workers - shop assistants, leisure industry, building etc, whose products are no longer affordable. Add to that a million British workers returning from the EU and there is suddenly a glut of workers and no work. People will be unable to leave the UK and take their skills elsewhere, so people will be fighting over any job at any wage just to stay in employment.