Lots to look at. As mentioned, warm v cold cache can matter. Did you run it multiple times on the VM?

You restored, did you update statistics, rebuild indexes (only the latter needed in most cases) to ensure you don't have issues there or fragmentation.

More vCPUs doesn't mean more power. It should, but depends on how heavily loaded your host is. Make sure your memory isn't overallocated, and above all, you need to make sure you have good IO throughput. Lots of times the default settings with IO aren't necessarily better than a physical machine.