Idea to make gpu's that can be put into the ODD for laptop's

So the idea is to make a gpu that can be put into the ODD slot and somehow connect it to the motherboard.
This would help upgrade older and newer laptops.
As this would allow the laptop to be as powerful as it would have with a external and be more mobile and possibly cheaper. Disk drives are becoming less useful and why not use the extra space for better gpu’s make them more powerful. All we need to do is find a way for the cable to get through the drive compartment and into the motherboard compartment.