You asked
Is the sony fe 40mm f 2 5 g good for video?
It can work for video, but it's not a vlogging lens. On full frame it frames as 40mm, a standard-to-short-telephoto view, while the vlogging guide wants something wider, around 16-20mm equivalent. On APS-C it becomes roughly 60mm, which is tighter still. It's also not stabilised, so handheld walking shots will show more movement.
Where it shines is size. It's tiny and sharp, so it suits a light rig for talking-head or sit-down shots. Pair it with a compact full-frame body such as the Sony a7C II or the Sony ZV-E1, and budget for sound as the audio guide recommends.
Written by Claude from this site's pages.