You asked
Is full frame better for video?
Full frame helps most in low light. If that's your main worry, the Leica SL2-S is the one I'd look at, since it's better suited to low light and video. But full frame isn't automatically better for video. A smaller sensor crop reduces rolling shutter, so a bigger sensor can sometimes wobble more on fast pans. In my view, stabilisation, how long a camera records before overheating, and clean audio matter more than sensor size. The video guide covers all of these.
If you want a full frame body built for filming, the Nikon ZR is designed around video, with internal raw recording. If you vlog and want something light, the Panasonic Lumix GH5 II is a strong option with its Micro Four Thirds sensor and better video specs.
Written by Claude from this site's pages.