That approach works really well when you have a stable shared base image.

Where it starts to get harder is when you have multiple base stacks (different CUDA versions, frameworks, etc.) or when you need to update them frequently. You end up with lots of slightly different multi-GB bases.

Chunked images keep the benefit you mentioned (we still cache heavily on the nodes) but the caching happens at a finer granularity. That makes it much more tolerant to small differences between images and to frequent updates, since unchanged chunks can still be reused.