Some of the images that appear in example/docker-compose.yml are very old. Example:
- prometheus v2.25.0 (2021-02-17)
- grafana 7.3.7 (2021-01-14)
- etcd 3.4.15 (2021-02-26)
I'd offer a pull request to update images but I haven't found any compatibility matrix or other information on what has been qualified for use with APISIX.