Hmm.
I think most people can achieve some sort of "financial privilege" with some form of financial planning and living within personal means.
I'd say SOME people can achieve that, if by privilege we mean doing a weekly shop without holding your breath at the till, being able to absorb the costs of a new boiler, new winter coat, kids' shoes etc. And maybe some, though fewer, can also achieve a further-reaching financial privilege by doing financial planning and living within means - so maybe an annual holiday or two, private school for kids, nicer house, nicer car, investments?
Some can't because they aren't savvy enough to (which can itself link to privilege/financial understanding), some are too focused on spending money on shit, some have rotten luck or difficult circumstances, some have so little money that they can do everything right and still get nowhere.
I'm financially privileged now - 34 and approaching never having to work again though I do work, I run a food bank. What frightens me is how money begets money, and how that can work for or against you. I immigrated to the UK with no financial or other resources and worked like a dog. I made unpleasant decisions, took jobs and then a career I didn't much like because it was lucrative. At the time I really could have used a bit of financial privilege! I had luck and willpower. Now, however, when it doesn't matter much at all, I have all the time in the world to shop at Lidl, compare energy suppliers, hunt out discount codes, sue companies who provide me with shoddy service, do repairs to keep an old banger on the road etc.
And then the cycle continues - I have a daughter. I have the time and energy to sit and read with her for hours. I can follow up on her interest in X with books and activities and YouTube videos. She eats home cooked food, goes to extra-curricular activities, has lovely toys, a warm bed, a calm home. At three she is bilingual, reading, can dress herself, solve problems, has friends she's known her whole life etc. And in two years she'll go to school and next to her may be someone whose parents are working three jobs between them and don't have as much time as they want to spend with their children, move every six months at a landlord's whim from one damp or overcrowded home to another and eat a poor diet of things that can be cooked quickly/in a kettle if no cooking facilities, or suffer food poverty. That's where the real effects of privilege kick in, imo.