I dunno if you hadn't realised but the land sale by Real Madrid was over 20 years ago and was for less than 245m. That isn't what is making them sustainable today in 2024.
Bro you're just trying to change reality to fit your own narrative. About half the clubs in the list are working to sustainable means. It's really only Chelsea, City and PSG that buck that trend.
Barca is a slightly different story, they have high revenues and high costs but the very strict La Liga spending rules that have hampered them in recent years, not an actual lack of income or cash flow to a lesser extent.
The Real Madrid land sale is not relevant, yes they have (and a lot of European clubs have) worked to a sustainable model recently
Barca is fudged mate, massive debt, they have sold component/futures/rights forward for years, no amount of income is going to help them out of that position.
The reality is (to your point perhaps), lots of clubs (lesser so in PL) are working towards sustainability (as if it's some big fudging surprise that a business model should work vs. being a constant money pit). We have always run that way, so hopefully for all the handicaps it's given us in the past, it provides some advantage now.