> that it's not simply an issue of pay, and there aren't enough Brits willing to do those jobs.

From what I've read (and take this with a pinch of salt) there are a lot of licensed HGV drivers in the UK who don't drive anymore, with common reasons being long, unsociable working hours, management that treat you like dirt, shitty rules around where they can park to take rest stops with substandard (typical everywhere in the UK...) facilities, and pay that hasn't risen in decades.

This, combined with not enough younger folk taking up the job, along with Brexit, has led to a shortage