Edit: This applies to countries with relatively reasonable populations with respect to their resources. This does not apply to places like China and India where there is a huge population to support.
This is all true - and all of those are possible while still being wealthy. The peculiarities of US culture are different from being wealthy. As another example you don't need to have an obsession with guns to be a wealthy country, but the US does.
Similarly, the average American making over $40k a year will not consider themselves the 1%, but to the average citizen of the world they are.
People who own homes in the Bay Area do not have massive disposable income. But they do have wealth.
Now that same family, income and house with a paid off mortgage is in an entirely different situation.
The difference is the wealth they accrued in paying down their mortgage. They claimed value in doing so. But merely having a massive mortgage in the Bay Area does not _inherently_ equate to wealth.
There are definitely subtleties, like how feasible it would be for you to reduce expenses while keeping your income the same. Life.. gets complicated.
It's been said many times before about similar statements, but this is not true or mathematically possible. I believe it's off by about an order of magnitude.
Middle class in the US is something like $45,200 to $135,600 in household income, which is roughly half the population.
Half the population is about 2% of the world population. And every American is not wealthier than everyone outside the US.
If you google something like "global income percentile" you will find a considerable amount of BS claims - the first one I found was on Investopedia. For fun or ideology or whatever, the meme that middle class Americans are in the top 1% is something that people will just go on the internet and lie about.
I didn't spend enough time looking to find really satisfactory sources, but in trying to find something relatively unbiased I ended up with something that suggested the US middle class might very roughly be around the top 10% globally.
Source: https://www.pewresearch.org/global/2015/07/08/a-global-middl...
(Note that in the terms of the linked article, it seems like the global middle class is a tier below the US middle class, so if about 85% of the world is "poor" or "middle class", then the remainder or 10-15% equates to the US "middle")
"Workers in America don't need better pay or benefits, they're already wealthy by world standards!"
"Workers in China don't need basic safety protections and sane work hours, they're already better off than workers in sub-Saharan Africa!"
Any middle class American is wealthy by the world's standard. The quality of life provided by middle class America is the life of the 1%. To not see this is to not understand how most of the world lives, and the challenges people face from being less lucky.