The article you’re linking to is clickbait, by someone who doesn’t live there. I lived in Miami for most of my life, a second-generation native, and I’m buying a house there for a move very soon. So a few facts here.
Miami will be underwater eventually, but it’s going to take a very long time. The claim that the city is built on limestone is accurate, and it is porous, which will cause saltwater intrusion problems in the lowest lying areas. But it’s also rock hard and higher elevation in the oolite ridge along the southeastern Florida coast. The King Tide flooding is only happening in the lowest lying areas like Miami Beach, and yeah, that place is going to suffer the worst and the earliest flooding. Bad idea to buy real estate at sea level, duh.
But most of Miami is at higher elevation. The last house I owned in Miami was 1,000 feet from Biscayne Bay, but 43 feet elevation above sea level on the limestone rock ridge that most of Miami is sitting on.
The house we’re buying now is further inland, and 27 feet above sea level. It’s going to be a long time before the ocean rises that much. It will rise, but hyperbole about how fast it will happen is not helpful.
If you want a real estate investment that’s secure against climate change for 100 years, then yeah, there are parts of Miami you shouldn’t consider. Go to Montana, maybe. Meanwhile there are reasons why it’s still a hot real estate market, and it’s not just climate denial. But you’d have to live there for a while to understand it, like anywhere else.