Modularity/expand-ability comes at a cost. Both monetary cost and performance cost. We used to have gpus with expandable memory but we dont anymore.

Thats because by having the memory integrated into the board, we can put it much closer to the chip, greatly increasing the bandwidth and lowering the latency. This is exactly what Apple has done with its memory and why it isnt expandable anymore. Apple’s memory is 5x+ faster than ddr5 in terms of bandwidth. Also you fully take advantage of the entirety of the available memory bus, instead of having empty lanes chilling for potential upgrades.

By having an integrated battery, you can have the battery have all kinds of wacky shapes that fill your design better.

Having a microsd slot takes a lot of space and can result into a significant degraded user experience if the user uses a slow microsd. And even a fast microsd is slower than integrated storage.

All these things are possible but they come with some sacrifices. Part of the change is because of enshittification but some changes is because they make sense.