I also had that misunderstanding, so after seeing this comment I looking up info. In this article you can see the xray of the m1 chip composited onto the photo of the chip, which has external memory components. You can also see in the architecture diagram that the memory is attached from outside the area where the Fabric, CPU, GPU, NPU, cache, and some other unlabeled things are located. https://www.macrumors.com/guide/m1/

And in this article you can see a photo of the memory chips attached outside of the Apple component https://www.gizmochina.com/2020/11/19/apple-mac-mini-teardow...