Often the way, I see so many parents who give their kids all the support they could ever want, only for those kids to simply waste opportunities and talents, whilst so often it's kids who, whilst by no means unloved by their parents, have to fight to for opportunities who seem to shine. Having said that, there are a huge range of factors that will moderate the support/success equation, not the least of which personality (in both the nature and nurture sense); some kids are just destined to waste opportunity whilst others seize on it, so at the very start of things you have the interaction of high/low support parents and high/low motivation kids.
I think that I would have done better with more support, my Dad simply wasn't interested, in fact despite not being a musician himself he saw fit to criticise every instrument teacher I had, and my Mum was of the 'that's nice darling, you got Grade 8, you can have an extra sausage with supper tonight' type.
A pivotal point in my life in fact came when my tutor told my father that without a better instrument I wasn't going to progress. I was studying Grade 8 at the time, I think I was 13 so pretty decent for my age. She advised buying new, not because it was a better decision, but because in the days before the internet, buying used was more problematic. She gave my Dad a list of instruments in descending price order, and was explicit is saying of the bottom one "Do not buy one of these". We went to the shop she'd recommended, I played about 20 instruments, and he then said "You're having that one, it sounded best" which was of course the one my tutor has explicitly stated not to get.
It was 40 years ago, but still makes me angry. His attitude was characterised by "I'm not going to have some snotty orchestral teacher tell me what to do". If she's said 'Do not spend £10,000 on ........ as those instruments are rubbish" he'd have bought one just to fosters her off