Does it mean, that Client have to buy Enterprise for this 80 v-cores?
If you have enterprise edition installed on VM which has 80 cores (including hyper threading) you need to license all the cores. This is what MS licensing says for Virtual machines. For physical you would have to license "physical cores" though.
Standard SQL works with 24 core maximum.
For standard edition MS says lesser of four sockets or 24 virtual cores. So which ever is lesser will be counted, rest cores will be ignored in standard edition