For the 3 grand in sacrificed allowance you’d get a lot of lessons and by the time you pass your test there might be something better of more suitable on the scheme by then.
There is always the possibility that it could take you a few attempts to pass and you could end up running into another year easily, at this point the free lessons would have run out and you would have a car you couldn’t drive that you were still paying for and a whole new set of lessons to fork out for as well, hell for 3 grand I’ll come and give you lessons.