Buying a house needs a bank account and other things and then someone in the chain eventually asks "where did you get this money?" and unless your answer is "I have owned these sweet shops in central London and empty takeaway restaurants for decades and they unfortunately only deal in cash" then someone will catch you.
There’s more than a few wealthy former corrupt officials having a nice comfortable life in countries in south america or countries like Malta, cyprus etc…
It’s harder if you don’t have much money (used to be relatively easy with a low amount of money but the oecd has been very efficient at tightening things for people with less than a few millions)
Russians buy houses in Cyprus. A lot of high end houses in London are owned by iffy money.