Perhaps in some EU countries, there is a policy implication because education is of more variable standard, and not merely thought to be variable by parents who would have liked to obtain competitive advantage at pre-womb stage... This is true in some non-EU countries, where tutoring is a practical and not ideological option. If a child is bright/interested enough, within a short time say two years after leaving any UK/similar school, tutoring won't have done any good and may possibly have damaged their confidence.
That said, I can't help thinking people should generally spend their effort and money how they want. After all we don't mind if their shoes and clothes fall apart in a few years, why mind about tutoring?
Personally I've never seen the attraction of wasting what little time children have in their lives on tutoring. Mixed ability teaching may be a struggle, but such classes are rife in plenty of super-competitive schools, they manage decent enough results. It's actually quite hard to get a D at GCSE in something you like/have engaged with, if you recall that old style O level pass grades (1-6) only went down to C equivalent, and that was before grade inflation and the really really obvious syllabuses and examination material we have these days. But that's another subject altogether. As for post 16, mixed ability teaching is even more common, if you think about the gap between year 11 and 13. After year 13, ranges of ability being taught together increase further. Etc.
Children make the effort if they enjoy something. If they don't, and you can't ignite that interest, after you've had your way with them for the first eight or more years of their lives, in a stable and relatively well-educated country, how do you think a paid stranger can?