The CPU steal time is the time the virtual core is waiting for the physical core. That means a VM is waiting for the hypervisor until it shifts CPU time to the VM again. More virtual cores sitting on a physical core means higher CPU steal. And higher CPU steal means bad performance because the hoster is allocating more virtual cores on a physical core that it can manage.
The CPU steal time is the time the virtual core is waiting for the physical core. That means a VM is waiting for the hypervisor until it shifts CPU time to the VM again. More virtual cores sitting on a physical core means higher CPU steal. And higher CPU steal means bad performance because the hoster is allocating more virtual cores on a physical core that it can manage.