Postgres (Docker provided - https://hub.docker.com/_/postgres): Debian (with alternates for alpine or other debian versions)
Jellyfin (Developer provided - https://github.com/jellyfin/jellyfin/blob/master/Dockerfile): They use an alpine build step but the final distributed image is debian
Calibre-Web (Linuxserver provided - https://github.com/linuxserver/docker-calibre-web/blob/maste...): Ubuntu
Graylog (Developer provided - https://github.com/Graylog2/graylog-docker/blob/4.2/docker/o...): Debian
Vaultwarden (Developer provided - https://github.com/dani-garcia/vaultwarden/blob/main/docker/...): Debian (with alpine alternate available)
I'm finding it hard to reconcile "Some of the software has secondary alpine images available" with "Almost all software uses alpine images"
For professional use, our company mandates all images used are built off a common base image, which is Ubuntu based (my previous employer was similar, but used a Red Hat based image).