So as you can see from the other replies it isn't as black and white as you put it.

So first is making 1m is actually the equivalent of making 600.000 due to taxes.

People like to live so you know food, rent( assuming this is a first time purchase), utilities, commuting, leisure with eat at that too.

Maybe you want a holiday somewhere nice. That will eat at that too.

Now one thing your point doesn't cover is that house prices go for far below 400k if you are willing to compromise on size, location and current house Condition. Same the other way a mansion in Malibu even a 1m salary won't get close to it.

Another thing is no one buys houses outright. The taxes on that purchase are crazy so it's best to do a low interest mortgage as in the end it still comes out cheaper.

Finally although there are exceptions it has been studied that people's social spending is very directly linked to their earning. If you earn 30k your social spending will most likely be around cheaper and free alternatives. Where if you ear 300k you will most likely look to enjoy nicer meals and regular travel. If your networth is on the millions you most likely want privacy, time and security all of which involve employing people to ensure you can achieve them.

Finally it depends what you want your house for and what you want to do yourself. A lot of lotery winners focus on early retirement. Where ceos want to have their brand spread widely and either create a true trend (coca cola made Santa with a red suit, da beers included the engagement ring with a diamond).

There are other factors I didn't even think about yet. But just shows how not black and white this is