They lost access to a naval host in the Mediterranean sea, a land corridor through Iraq and Syria, trade route protection through the Suez canal and the Red Sea, and whoever ends up ruling Syria will be a US puppet that will block Chinese investment in the country. That one base could have cost the US billions of dollars and created a balance of power in the region.
They could have and should have overthrown him if that story was even true, which I do not believe for a millisecond. What these two have lost here is incalculable.
I was talking about China's own interests rather than saving Assad. Assad is safe and sound. He will live a long and happy life away from all of this chaos. Regarding Taiwan, I used to think China could wait the US out, but at this point I have absolutely zero faith that China will ever recover Taiwan. They don't do anything about anything at all, even when it's simple cheap things. Even Pakistan still double deals on them with the US, allowing terrorists to blow up Chinese infrastructure inside Pakistan and China sells their J-10CEs to them. Myanmar is still getting obliterated by US backed terrorists right on China's borders. The Philippines, SK, Japan, all still host the US and are completely owned and operated by the US and China still does nothing about it.