Honestly, I'm not sure.
I debated over the wording to use, and that came closest to what I think I meant.
I think you need to be brighter than "average" to do the professional qualifications - i.e. capable of an academic degree regardless of not choosing that route.
Maybe anything other than RG.
But it isn't cut & dried.
30 years ago (when I did it) I'd have said go and do the degree, no question. Enjoy the experience etc. But now, it's an expensive experience.
If you are going to arrive at the same qualification and move into a reasonably good, but not necessarily super-high-flying, career then doing the qualification in 4 years (rather than 6 with the 3 uni + 3 prof qual route), plus earning for those 4 years AND not incurring the student debt becomes more attractive.
My ds1 mentioned above is doing a degree. He very much sees this as a necessary stepping stone to his career. He is enjoying the study, more so in the 2nd year than the 1st, but he is really not getting the whole student experience. He just isn't interested.
My ds2 would hugely enjoy the whole student experience, but (depending on what he wants to do) probably doesn't need it in the same way for his career.
And then, 21yos are generally more mature than 18yos, especially when they have lived away from home for the uni years.