https://www.jeffgeerling.com/blog/2024/use-external-gpu-on-raspberry-pi-5-4k-gaming
I'm still hoping that someone brings out a dedicated GPU for the Pi. Till then this is quite a good article on some of the issues that need to be sorted.
These are:
GPU driver with Arm support
Pi's PCIe only supports up to 5W of power
Then the adapters to get a PC card working
Though the one I really want is just a simple hat type thing that can add some of the GPU features that can't quite run on the internal GPU as well a some way to add a bit more power if needed.
Still fairly sure something like this will come out one day, till then we wait