What you're looking for is typically called shared-data architecture, where multiple database nodes access the same set of database files (a database) distributed across the nodes, and the database capacity approximates the sum of disk and CPU capacities of all nodes (more or less).
The MySQL cluster solutions you're referring to implement the shared-nothing architecture, where the database copies are replicated between nodes, and each database node works with its own "copy", so you're still limited by the disk and processor capacity of an individual node.
I don't think there exists a shared-data cluster solution for MySQL, as implementing it is a non-trivial endeavour -- just ask Oracle RAC folks.
If your workload allows, you might consider a cluster file system, such as CephFS or GlusterFS, which will present the sum of all servers' disk volumes as a single file system to a single database node. This will at least address your disk capacity requirement.