This is limitations of scylladb and their api service requirements.
They haves something called a service agreement. That means the API is required to respond in 99% 99.999% etc. and by limiting to 8mb for files, charging for a bit more etc. they can both monetize and enforce guaranteed api requirements internally.
He fired the worlds biggest experts on the technology at Twitter and thought he could do it better with a skeleton staff. Now the dead body rots. The skeleton is there. It smells musky, and the site has died.