If you want to do GPU-intensive work on a laptop that can’t fit a high powered GPU (some of the desktop ones are quite large), then you can put it in an enclosure like this and plug it in to your laptop.

The GPU equivalent of an external hard drive.

Right now (for my use case) it's primarily for GPU pass through into a Windows VM via Qemu/KVM.

If that doesn't work, and since it's just PCIe, I wanna try experimenting with setting up 10 Gigabit fiber to a home server.

I'm considering moving from a desktop with powerful GPU to a laptop + external GPU using a device like this. Would be nice working from a single machine both at home and away.

You can get a lightweight laptop with great battery life, then when you're home, connect it to a desktop GPU for gaming.

Anything that might benefit from using a desktop GPU, but doesn't justify buying a desktop machine.

With the caveat that desktop GPUs are most of the times connected via 16 PCIe lanes. Depending on the workload, reducing it to 4 lanes may seriously bottleneck the GPU.

Adding a GPU to a Mac, or anything with TB3 really.

Keep in mind it won't work on Apple Silicon Macs though, and I think Intel Macs have limited support for nvidia cards in macOS

Hardwarewise or just macos? What if you want to add the GPU to a windows/linux VM?

To my understanding, it's just a lack of support from both macOS and third-party vendors. There are numerous other reports of successful usage in Bootcamp albeit with some caveats.

Regarding VMs, and this is hardware dependent due to IOMMU groups (and is based on a Linux host), but I also recall cases where this is possible on reddit.com/r/VFIO