You are so right, and I blame some of the thinking on this very website. People are
adamant that they need to upgrade the RAM, change the storage, and replace the battery on their laptops.
Adamant. All that means that you need a separate memory controller, a separate this and that. It adds up, and PC makers are forced to put in a fan.
On its face, it doesn't sound stupid at all. The thinking that you need to be able to upgrade and maintain your laptop sounds elegant. But those people, they never argue that they must be able to change the CPU. Why not? It used to be that upgrading the CPU in a laptop was a common occurence. Why don't they throw a fit that they can't upgrade the CPU?
Because technology caught up with them. CPUs are now soldered on the board, for multiple very good reasons. Coupled with the fact that a good CPU is good enough for a very long time, and no one feels the need to upgrade their CPU on a laptop. Same thing with the math co-processor, no one's arguing to be able to change that!