system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Is there a practical reason why some brands make phones without removable battery / SDcard, or they're just fucking with us?
gpt
If you want to make the battery removable, the entire design of the phone is restricted by that fact. It's a huge design decision that's taken out of your hands as a hardware designer. How do you make a glass front and back like the iPhone 4? Or a aluminum phone like the htc one? Can you make the phone as sturdy if you need to be able to access the battery? It's  harder to make water and dust proof. Etc.

It will also inevitably result in some wasted space inside the phone. Space that could have been used for more battery.