Multiple disks vs single disk on virtualized environment
what are the actual benefits of doing so on the above described architecture (if any)?

There are some management benefits, particularly:

You get separate disk performance counters in the VM for Data, Log, and TempDb

You can migrate any one of them to a different storage device without reconfiguring the VM or SQL Server.

You can manage Storage Quality of Service seperately for each virtual disk, capping or reserving IOPS.

You get seperate IO queues in the guest VM which may marginally improve performance, especially in a scenario where perf-critical log writes are intermixed with large volume data file IO.