I mean, if your main PC isn't powerful enough to handle gaming and streaming at the same, then it might sound like a viable option, especially if you're gaming at 4K. In addition, the ability to edit/manage your stream stuff independently (layout, chat, etc.) is nice to have too, I guess, although that can still be done with just a separate display if you're not into dual PC setup.
W10Pro (22H2)|Kingston A400 240G|ASRock B550 Phantom Gaming 4 (L2.71)|Ryzen 5 5600|ID-Cooling SE-225-XT Black V2|nVidia RTX 3070 FE 8Gb|XPG GAMMIX D10 [2x8GB] DDR4 3200MHz (XMP)|DeepCool PK700D