Sansung SSDs for data centers exist, the PM and SM seriesSamsung Pro = consumer SSDs. Not recommended for production use. Is this a hardware or ZFS RAID? As I could see from your screenshots you’re running the VM on your local-lvm and SSD emulation is unchecked.
Bottlenecks should not be CPU and RAM, but your consumer SSDs. When plenty of users work on the server, the SSDs will run out of cache. Just my guess.