Standard in the context of a previously extremely poor former colony is a massive improvement that can only be attributed to rapid development and a people-focused government. As for the billionaire question, I believe I did via discussing markets, but I'll answer more directly since you asked. Yes, the PRC has billionaires, but it's important to judge the context of Chinese billionaires vs billionaires in Capitalist countries.

In the PRC, billionaires hold little political Capital compared to Capitalist countries, the strength they have as a class is thus limited. The problem with cracking down too hard on billionaires at this stage in Socialist development is the risk of Capital Flight. China's strategy is to encourage foreign investment and development, while maintaining government supremacy over Capital, in how it moves and grows. If they took a more hardline stance, they would potentially be decoupled from the global economy and end up as the USSR did. A good article is China has Billionaires by Roderic Day.

Moreover, certain entire industries are state owned, like the Steel industry, that the private sector relies on and thus must be bent to the will of the government, not the other way around. The public sector is the base of the economy. The Private Sector is also seeing increased control from the state, because as markets develop they centralize and make themselves ripe for planning, a concept core to Historical Materialism.

China isn't perfect, but it is Socialist.