I'm not so sure. The Russians have been effectively living in space for years- all they were really missing was the real estate to grow their own food. Sure, needs some tweaking, and ramping it up to colony scale will need some impressive infrastructure. But a couple of Musks get together with a Russian Oligarch or two and start something small but expandable, using SpaceX hardware or similar. I could definitely see that happening. Much easier to setup a habitable environment from scratch than to even comtemplate terraforming, living underground forever, or being geographically constrained like on the Moon. Plus, they would own half the earth, so easy to just pop back to the shops when they need something if they're just in orbit. Take the schmaltz out of Elysium and i think you have a workable model (speaking as a current Oligarch).

The problem will be - if it's not another planet it will be "somewhere". I see a vision like in "Elysium" as being a very realistic possibility in the not-too-distant future. It's already happening with tourism and it would probably be the most long-term cost effective way to escape the decay of the earth for the uber-wealthy.

COP27 proves that ultimately no government will do anything about Earth's problems until they are forced to. At which point the solutions are more expensive and difficult, and off-planet solutions will be more attractive.