My sister-in-law can't get married because she earns too much money

My sister-in-law is an unmarried woman in her mid-40s, a "gold miss."
It's not that she studied incredibly well, went to medical school, and opened her own clinic to make a lot of money...
Rather, she graduated from a university in Seoul and works in the financial sector, specifically at a financial holding company.
Since some people might not know what a financial holding company is, I'll just say she works at a bank.
Having stayed with this company since she started working,
her current annual salary is around 230 million KRW. It might even be more.
The amount deposited into her account after taxes is about 13 million KRW per month.
Her condition for a partner is a man who earns more than she does.
But... there are none... none!!
If she were a small business accountant earning 30 million KRW a year
and wanted a man earning over 230 million KRW, people might criticize her,
but since she earns that much herself, no one can say anything.
As all office workers know,
if you are single with a high salary, the taxes during year-end settlement are...
So, she spends a massive amount of money on herself. She says even after buying
everything she wants and everything she needs, there is still money left over.
On top of that, the apartment she bought in Seongdong-gu around 2010
is now worth over 3.5 billion KRW, and she has zero loans.
Because I always told her to invest in QQQ, she invested all her surplus money there, and that has also grown immensely...
With assets exceeding 4 billion KRW and an annual salary of 230 million KRW...
A man of her age who earns more and has more assets than her!!
There are none.
—Does that mean my sister-in-law is exceptional? No.
As I mentioned above, she didn't go to medical school; she graduated from a university in Seoul,
got this job 18 years ago, and as she worked, her salary grew to over 200 million KRW. As for the house, back then,
she just saved up, and as her money grew to 100 or 200 million KRW,
housing prices were cheap, loans were available, and interest rates were low...
so she bought the house, and she invested in QQQ because I strongly insisted on it....
My sister-in-law says herself that it was all just luck... that she didn't do anything special because she's talented... just luck!!
What my mother-in-law said:
;;If she hadn't earned so much money, she would have gotten married, but because she earns so well, she has nothing to lose... I think that's why!!
"She can't get married because she earns too much money"... those were my mother-in-law's exact words.
My sister-in-law lives with my mother-in-law, and I'm not sure about the house, but
I assume she rents it out or gets monthly rent, right?
With 13 million KRW hitting her account every month, she works, goes home, and exercises on weekdays, so she doesn't have much to spend... and eventually, she even started doing mileage runs...
You know about mileage runs for people who travel, right?
Now, my sister-in-law has given up on getting married.
Looking at her, she is the ultimate example of self-management.
My mother-in-law says with a laugh that she regrets calling her every night at 11 PM to ask when she'd be home
(Even if she had gotten pregnant out of wedlock, she would have gotten married...)