Gaza has a sizable coastline, and China has a large number of amphibious assault ships available. They can defend themselves against Israel air attacks. If China decides to send humanitarian relief to Gaza, China can do it, and Israel can't stop them.[3] China would look like the good guys. Which their leadership knows.
[1] https://www.foreignaffairs.com/china/chinas-game-gaza
[2] https://edition.cnn.com/middleeast/live-news/israel-hamas-wa...
[3] https://www.newsweek.com/china-amphibious-assault-ship-type-...
However, they have nothing to lose and everything to gain by brokering some kind of peace using their supply chain supremacy.
Meanwhile US looks more and more like a paper tiger because they can't stop Yemen from blockading Israeli shipments and also refusing to do the one thing that would resolve the shipping issues: force Israel to the table for a ceasefire.