Problem: Syscalls are expensive… Solution: An I/O model that works uniformly across all file types (!) that provides a general-purpose syscall batching mechanism, which cuts down on context switches and syscalls.
Problem: Extending the kernel safely and easily is hard. Solution: eBPF lets you safely execute bytecode in the Linux kernel without changing the kernel source code or creating a kernel module.
Problem: You want faster and leaner VMs/containers. Solution: Compile a slim and performant OS custom-made for your application.