I basically agree with you. The partition sizes (or should I call it disk space reservation) are most likely massive overkill for most use cases. It's similar to ESXi 7.0 itself, where a fresh installation will use up to ~128GB on the installation disk. Anyway, most modern storage systems support thin provisioning, zero detection, and other things, so that the whole disk space is not going to be used up front. For storage system without thin provisioning options, thin provisioned virtual disks may be an option.

André