there generally is no central shared immutable image store because every job is using its own collection of images.
what you're describing might work well for a small team, but when you have a few hundred to thousand researchers sharing the cluster, very few of those layers are actually shared between jobs
even with a handful of users, most of these container images get fat at the python package installation layer, and that layer is one of the most frequently changed layers, and is frequently only used for a single job
what you're describing might work well for a small team, but when you have a few hundred to thousand researchers sharing the cluster, very few of those layers are actually shared between jobs
even with a handful of users, most of these container images get fat at the python package installation layer, and that layer is one of the most frequently changed layers, and is frequently only used for a single job