I think of Old Money in the sense of stuff that isn't showy, but when you handle the items or see them up close, you know instantly they are premium items.

Clothes are the classic example. They don't have gaudy logos or anything like that to call attention to them. But they're stuff that you could hand down. Real quality wool, cashmere, the buttons themselves are premium, that kind of thing.

Cars again are more upscale touring types, not sports cars. The richest guy I've known drove a Hyundai Santa Fe. He spent his money on houses and fancy travel and his car was just for getting around.

New money is the showy and usually overpriced stuff covered in logos.

Simplest way to think of it is New Money is for newly rich people that feel the need to wave it around they've made it big. Old Money knows blowing it to impress people is stupid. You buy stuff that enhances your life and pampers you.

We live in a relatively low cost of living area and make decent money. We could pull off New Money if either of us cared about that. We cannot afford anything I'd consider Old Money. That's a whole different world.

preppy, Ivy League, business-casual style

these aesthetics come from early & mid 20th century style worn by wealthy "aristocratic" (not literally, they weren't nobles) American families. they rode horses, played tennis, rugby, and polo, wore school uniforms, etc. and their clothing reflected that.

that style was pushed into the mass market by Ralph Lauren, Tommy Hilifiger, and other brands. this meant everyone could afford those aesthetics. the old cars used to be much more expensive because they were imported and hand made, but modern production and shipping has changed that.

rich people now differentiate themselves in other ways.

The point is old money is not showy compared to new money. New money is Lamborghinis, modernist mcmansions and private jets. Old money is low key, they don't want to get clocked as being rich. Maybe they drive an old mercedes or wear ordinary clothes, but their friends know they have a controlling interest in a huge corporation, their own private island, etc. So sure, ordinary people can replicate much of the 'aesthetic', because its about rich people not wanting to seem rich.

the never ending quest for having more authenticity than anyone else

It's the same people who use the word bougie and don't know why.

Are you saying that aesthetic should be called something different because anybody can achieve it regardless of wealth? Why does it matter what it's called?