The reason why China is creating BRICS is that they do not want to depend on the US or the EU. They know very well that the US president can increase trade tariffs at any time according to his wishes. We have also been aware of this. When the US increased tariffs, China also responded by increasing tariffs. So they will not do any business with them out of fear.
The purpose of forming BRICS against the US and Western regimes is so that China can maintain its dominance. If China is not active here, then there would be no need for other countries to form BRICS. If BRICS is established, all the countries in its alliance will benefit, but China will be the most profitable. If this is the case, then why would China leave from BRICS?
China over the years has emerged as a big power in almost every field like economy, military, sports, though it's an established fact but it's certainly not liked by big powers of west and that's why we see continuous propaganda against China. BRICS is not a new alliance but it dates back to 2009 and good thing about this alliance is that it's still active and more countries are joining this alliance.
It's first time Chinese president was not able to attend BRICS summit due to schedule conflict. But that doesn't mean China skipped completely the BRICS summit held earlier this month, Prime Minister Li Qiang led the Chinese delegation in there. I don't think China will leave a forum that is giving him benefit and getting strength with every passing year.