(Replace "London" with "Bay Area")
(It's a very rare person who ever thinks of themselves as "rich enough." Most billionaires don't)
When an unbridgeable gap is opening up between even the traditional "elite" (bankers, lawyers, consultants, doctors and now software engineers) and the 1% you have a real problem with social mobility.
If a country has decent access to education, it's not unreasonable to aspire to reach the "elite" with some smarts, luck and grit. That fundamental hope is what ticks over the capitalist incentivisation we have based our economics on. It's what inspired my parents to leave their home country and climb many socioeconomic rungs.
If you remove that belief in the system, people start signing out of society and then you have a big problem. Like Brexit. Like Trump.
Then suddenly war doesn't seem so impossible anymore...