Basic framebuffer. You can browse the web (software rendering), code in Xcode (text editor mode), and run the OS at native resolution. But it is not a production environment.
macOS will boot, but you will experience extreme lag, "choppy" animations, and screen tearing.
If you only need a server environment, a Xcode compile machine, or a basic text-editing setup where fluid animations do not matter, you can force macOS to utilize a generic VESA frame buffer.
If you are building a productivity machine and do not need immense graphical power, you don't need an expensive RX 6800. You can buy a cheap, older AMD card solely to handle the macOS UI.
The Definitive Guide to UHD 770 Hackintosh: Enabling Intel Alder Lake/Raptor Lake iGPU Acceleration
The system cannot utilize the GPU for basic tasks, forcing the CPU to do all the heavy lifting. The Essential Workaround: Dedicated GPUs
The Ultimate Guide to UHD 770 Hackintosh: Compatibility, Workarounds, and Alternatives
The last Intel-based Macs used Comet Lake (10th-gen) and Ice Lake (10th-gen mobile). Those chips used the graphics architecture (UHD 630). The UHD 770, however, uses the Gen12 (Xe-LP) architecture.
The Ultimate UHD 770 Hackintosh Guide: Current Status, Fixes, and Alternatives