Firefox does only exist because Google pays for it. Google is Mozilla's single greatest financial contributor. They're essentially keeping a competitor on life support to avoid breaching antitrust laws. Essentially, the argument is that as long as Firefox exists, Google isn't a monopoly.
However, at any time, Google could simply stop paying, and Firefox would quickly die. Laws change.
In the first minute of that video, it depicts someone walking up the stairs, writing with a pen, and closing a cupboard. All of these scenes and movements were really well animated, actually. I didn't see any awkward standing or wobbling that seemed out of place.
Random diagnostic question; are you an anime fan? I ask because anime often has scenes where people kind of just stand there completely stock-still and talk, with the camera moving around. The art style is a bit reminiscent of anime, so I'm wondering if the movement is coming across as uncanny-valley due to the similarity.