Careful, it's not the base image size. It's the environment size. If you don't put enough in your base image, you will have bloat everywhere. If you put too much, it will cause slow start (caching takes a while).

It's a balancing act. It's not easy. But, if you use a package exactly twice in your environment, then putting it in the base image actually makes sense.

Think at scale, not about individual images.