Point to remember- they are number 4. And beating a fast rising azure is going to be close to impossible.
A service that only exists in China to serve the Chinese audience may be bigger than worldwide services that serve worldwide audiences, but it's kind of irrelevant if you're not a Chinese company doing business exclusively in China.
They may have numbers due to Chinese usage, but no Western company is going to use Chinese hosting, ever.
IBM's *-as-a-service ARR is larger than Google Cloud's.
Oracle claims theirs is too, but my understanding is that they roll a lot of their licensing costs into the same reporting, so it's hard to tell for sure.
This gives Alibaba a huge advantage domestically.
Funny that China has a new law allowing them access to any data stored there, so it may stick to operating only in China...