There is no way to list servers without details, see https://docs.openstack.org/api-ref/compute/#list-servers vs https://docs.openstack.org/api-ref/compute/#list-servers-detailed

A simple comparison for 1k servers listing:

$ time curl -s https://nova:443/v2.1/servers -H "X-Auth-Token: ${OS_AUTH_TOKEN}" | jq -r '.servers|length'
985

real    0m1,907s
user    0m0,097s
sys     0m0,015s
$ time curl -s https://nove:443/v2.1/servers/detail -H "X-Auth-Token: ${OS_AUTH_TOKEN}" | jq -r '.servers|length'
985

real    0m20,425s
user    0m0,117s
sys     0m0,039s

simple servers listing takes 10 times faster results.

Proposal:

1. implement a NEW ListNoDetail function to list servers using listURL(client) call, keeping the backward compatibility for gophercloud
2. rename current List func to ListDetail and implement a new List func using NO-detail URL. This will break backward compatibility. Nevertheless I prefer this solution, since other API calls do have ListDetail functions, e.g. nova images, flavors, manila shares and baremetals.

see also: kubernetes/cloud-provider-openstack#2089