Presumably, you’ve already benefited from 13+ years of government funding into your education

Nope. I got most of my schooling overseas.

I assume you’re using roads and paths that the government at some level has built

Roads and paths that cost a shit tonne less to maintain for cyclists than they do for heavy cars and trucks. Trains which are subsidised to a much lesser degree than cars are.

If parents want to fund executive bonuses, swimming pools and whatever else above that

But you can't split it up like that. If a school spends 40% of its budget on marketing and executives (number entirely made up), then for every dollar the government is giving them, 40 cents of taxpayer money are going to fund private school executive bonuses and marketing. Even if that money went through a carefully-controlled process where it goes in a special trust account only to be spent on specially-approved student services, it's still in effect subsidising those other things, because it means the non-trust money doesn't need to be touched to spend on student services and can instead focus on the less productive purposes.

You’re still focusing on the schools and not the kids

No, I'm focusing on the money. I'm focusing on getting the best outcome for our education system. And that's to spend every cent we have on the students, not on executive bonuses and excessive marketing.

To the extent that I'm focusing on anything other than the money, I am focusing on the kids. I'm focusing on the kids who can't afford to pay for private school. I don't support funding private schools for the same reason I didn't support the original stage 3 tax cuts. It's a hand-out to the wealthy that they don't need.

It's just absurd on the face of it to support funding a highly profitable private sector when the equivalent public sector exists, is underfunded, and gets much greater bang for its buck. There is no angle on which one can approach it and justify spending public money on private schools other than corporate greed.