I think this is true for any RDBMS, though. If your block device has high latency, you will see bad perf when the DB tries to fsync.
But the block device latency is usually a order of magnitude lower (microseconds) than the network latency between the database and its clients (milliseconds), except when all clients are located in the same datacenters.
”Network filesystems” means stuff like NFS. Networked block devices should generellt be fine AFAIK.