Edit: also, big brands like Aukey have stock available next to you, so there's only one middle-man (Amazon), and it handles the logistics, so it's not like it's doing nothing…
Usually that's all
If the guy sucks, you go to another one.
You can see a company called Ugreen, which ended up with multiple "official stores" on online marketplaces this way.
Contract enforcement in China is of course non-existent. It's good if you manage to get a prominent handle for your own brand, in worst case somebody else can do it for you!
I know a man who regularly have to smack pretender "official stores" of his brand few times a year.
This also works the other way around, somebody with a vicious lawyer can coerce Alibaba, or JD into handing your (likely well doing) online store to them on a claim that you don't own your own brand name.
Otherwise, they are not that different from most other big retailers.