My and DP are currently saving for a house deposit, and by not having any debt we are going to be able to get a significantly better mortgage rent than we would otherwise.
Alternatively, you could be paying 9% of your income over the threshold while your parents give you the deposit and you immediately buy a house, rather than renting, which is (I would guess) a larger outgoing than 9% of your income over the threshold.
Comparing these two scenarios is not remotely easy, and a lot depends on the extent to which you regard "being debt free" (even though this being the only sort of debt in existence whose repayments are almost entirely decoupled from the capital sum) as being a moral good worth spending money on.
I modelled various scenarios for my children, and there are very few (most of them about rapidly being high earners) in which early repayment or not taking the loans in the first place is preferable to having the capital sum. If your parents are rich enough to pay the fees and living costs from income, or are rich enough that they can pay the fees and loans from capital without significantly impacting their ability to later give you more, then the situation is different: the rich are different to us, and all that.
My modelling of course depends on the sets of assumptions I used and a couple of bits of integral calculus on which I was a bit shaky and had to use Wolfram Alpha to cover my blushes but I'd be surprised if the basis that people are arguing differently is any better supported than my decisions.