Until the law changes that requires a minimum experience level before flying aircraft over certain weights, then a newly qualified CPL/IR straight from L3 or whoever, will occupy the RHS with low hours.
It is exactly what BA, Aer Lingus, Easyjet etc do. If it didn't work they would not do it. And you don't need to be a "wonder kid". Just a hard working competent junior birdman.
BA have been sponsoring cadets for years. Remember Hamble?
AerLingus likewise training at Oxford & BAe?
If the "white tails" wish to spend their money on a CPL/IR, that is a matter for them. Whether it is wise in all cases, that is the risk they take, knowing that employment is never a certainty.
As for T&Cs, a function of market forces, and what the Unions achieve through negotiations with the employer in a democratic European society.
And finally, not all Turbo Prop Captains are capable ( a small minority) of making the transition. Some have actually tired it, and given up the unequal struggle, returning to the turbo prop world.