What does "Does not have minimum availability" in k8s mean?
As @Tensibai indicated in one the comments, this could be caused as there is insufficient CPU or memory, but that is not always the case.
For example, a helm chart was just deployed, it failed and the workload in GCP indicated that:

Pod errors: CrashLoopBackOff

Based on the comment of @Tensibai the first impression was that there were insufficient resources, but further analysis using kubectl describe pod &lt;pod-name&gt; indicated that in this case the livenessProbe check failed:
Liveness probe failed: Get http://10.16.0.13:80/: dial 
tcp 10.16.0.13:80: getsockopt: connection refused

In summary, the Does not have minimum availability message is generic. Multiple issues could trigger this and more in dept analysis is required to find the actual error.