deserves? no. you have to earn it.
those that earn it aren’t scrooge mcduck ... they aren’t going to roll around in their billions in their bedroom. they’re going to at least put it in the bank... which will get lent out to other business owners who will pay their employees, or invest in more R&D, or etc.
Most likely they will invest it in the stock market or possible let it ride as venture capital for a new company. either way, the money again helps fuel other companies... companies who’ve been investigated and believed to have the highest chance of success, and therefore highest yield, going into the future.
this is how capitalism helps to ferret out those companies best suited to survive
this is also the reason why capitalism succeeds where socialism fails... the decentralized control of investment capital through individual scrutiny and self interest (to earn more money via good investments)
Not only do those billions get invested as you point out, allowing the economy to grow, but all those mansions, yachts, private planes, etc., have to be built and maintained by working people.
Take yachts for instance. Virtue signalling people might say "nobody deserves a yacht while people are homeless" or some such nonsense as that. Yet if the rich stopped purchasing yachts, an entire industry will be wiped out, with many thousands of working people getting laid off and some of them will BECOME HOMELESS!