To make it clear the issue is that the UK lacks local drivers, this issue was compensated by the fact that supply chains could use long haul drivers to do part of the job, with Brexit and the pandemic border frictions have increased and long haul drivers are not as easy to find or convince. So as I said the issue is the lack of local drivers but it's not a new thing and the reason people notice it in the UK is border frictions.
Again, I've not heard anyone in the industry claiming this is a major issue. If you have a source I'd be interested to read it. This is what's being cited as the major causes of the driver shortages in the UK, at least what I have heard and read.
1. Due to the pandemic a lot of EU nationals returned to their home countries, this demographic were disproportionately employed in the haulage sector, this happened in all European countries I believe. The issue being in the UK that due to Brexit they couldn't return.
2. Due to the pandemic 40000 HGV tests in the UK were cancelled.
3. Ongoing structural issues in the UK haulage sector, partly caused by the race to the bottom that cheap EU labour allowed companies to partake in, has left haulage jobs unfit for purpose in a first world economy. This has led to an aging workforce and a struggle to recruit younger people into the industry.
4. Due to the age profile of UK drivers, a disproportionate number of the workforce have reached retirement age during the pandemic whilst point 2 has led to those drivers not being replaced.
5. Due to the pandemic many people have reconsidered their priorities in life, a larger number of drivers than expected have taken early retirement or moved into different sectors.
6. Due to the pandemic the demand for delivery drivers to work for home delivery companies like Amazon and Tesco has increased significantly, a number of drivers have moved into that part of the industry and are not looking to return to the nationwide haulage sector
7. The record number of young people in further education means the the pool to recruit young drivers from is getting smaller each year.
I'm not discounting that your point may have some effect, it's just that I've literally heard no one talking about it as one of the major issues.