Billionaires shouldn't exist at all. Their very existence indicates that labour exploitation is taking place. Jack Ma didn't become one because he was some ultra visionary individual , its more to do with his workers (996).
Also everybody getting richer doesn't show the full story. When studied in depth it shows that vast majority of wealth generated in a year was galloped by the richest 1 %.. Infact last year the 1% owned more wealth than the bottom 50% and this gap is only increasing.
Eventually you'll reach a stage where GDP growth slows down to 2-3% and in that situation incomes of the lower strata will stagnate but rich folks will become richer (just like what has happened in US).
But as long as CCP remains committed to socialism and wealth redistribution we don't have anything to worry about.
Well, the thing is, if billionaires don't exist in your country but they exist in other places in the world, you will lose the people with creative ideas to those places.
Secondly, there should definitely be laws in place to prevent exploitation of workers, and I think those laws can play a great role in improving China for the average citizen, however, there is a line. If a company makes enough money to pay all of its workers fairly and for them to have reasonable standards of living (as determined by their skills), the owner keeps the rest. And if that makes him a billionaire, he deserves it. He doesn't have to divide up all his wealth to the point where janitors start earning 6 figures just because "billionaires shouldn't exist." This is exactly the type of socialism that doesn't work.
A country should be focused on getting collectively wealthier and improving everyone's standard of living. As long as that continues, as long as there are less and less poor and more and more people living a sustainable and affordable lifestyle and as long as the median/modal standard of living is improving, it is perfectly fine that the uber rich are pulling up wealth even faster. Social instability stems from having too many desolate people, not from the jealousy of those with growing wealth against those whose wealth are growing even faster. Making your rich poorer in order to reduce the wealth gap is the most self-destructive way to go about it.