When you look at the big engineering firms offering these "degree apprenticeships", it doesn't take a genius to work out where many of the traditional airline applicants are going.
I fly at a gliding club and we have our own cadets who basically get heavily subsidised/free flying in exchange for completing various straightforward tasks on the airfield. Historically, many of these went to the airlines as pilots, however more recently, they seem to be going for engineering. One went to Rolls-Royce in Derby and another has got himself a full-time job inspecting and repairing gliders which he seems to enjoy.
As for pay, an 18 year old school leaver could join an accountancy firm and be on £35-50k with no debt by 23, with good prospects for a Corporate Finance/Investment Banking gig (especially if they're an auditor). Can't say I'd do accountancy, I've done a small amount of related study and it bored me to tears but that's where the money is for school leavers these days.
As I've mentioned on a different thread, there's an excellent video of the training on offer at Hamble in the early 70's, what has happened since has been tragic really. If airlines are short of good applicants these days, they need to create a scheme which rivals what Hamble had to offer. There's only one or two airlines who offer this and I'd guess they have a very nice pool of applicants to select from.