Many of us have (or had in our younger days) all that's needed to be a train driver, yet we don't apply to be one. I think that says a lot about a decent rate of pay being needed to attract enough staff.
As has been said many times here and elsewhere, driving trains, especially fast ones, is a very responsible, high-pressure job, which takes a lot of training and there's not many that make the grade, never mind the shift work, especially if you're driving freight.
Much of the railway can replace humans with technology, down-skill or short-staff from time to time, but without drivers the job literally stops, so not surprising the ToCs will get their cheque books out to acquire and retain. One of the perks of a fragmented railway if you're a driver I suppose.
From time to time it pops up in the media, but for many, there's long been a realisation that you you can get far better rewarded and enjoy better job security in a highly skilled "blue-collar" job than many "white-collar" professions, especially now that AI is automating so many tasks. I'd certainly have no problem with my kids being train drivers.
