KVM switch is the easiest way, you just plug both GPUs into your monitor, and switch between the two depending on if you want to see your main system or your VM. The Archlinux wiki also talks about "Looking Glass" which passes through the VM's display to the main system. I haven't tried this so YMMV. Alternatively you can run Sunshine inside the VM and stream to the main system. Maybe overkill if you are only using a single PC, but if you've got other devices you can stream to those too.
As a veteran to VFIO and GPU passthrough, I would recommend the KVM option first. It's often worth buying cheap workarounds to start with, before diving into complicated software and networking setups like Looking Glass or Sunshine.
Sunshine is actually pretty easy to set up. Just install it on the PC, and connect from a Moonlight client on the same LAN. The complicated part is if you want to get fancy with the networking, for example if you want to access it securely from outside the home, or if you run Sunshine inside of a VM and want to access it from outside the host. But if your laptop can handle the games you want to play, turning it into a game streaming server should only take an hour tops. Definitely easier than messing with passthrough and virtualization.