Yup, a house sale or a fully vested 401k are often ways people meet the financial requirement.
The UK is very anti-immigration (as is the USA) at the moment. But believe it or not, it's actually much harder to meet the requirements to come this way. And a hell of a lot more expensive too.
If you were to apply today, I'd budget that it'll cost £12,000 over the next 5 years in visa fees. It's truly daylight robbery.