The video is probably factually correct, but very disingenuous with its interpretations and conclusions imo.
Of course Mozilla and Firefox have their own share of problems and bad decisions, and they are pretty well known and talked about from what I've seen, but equating it to Google and Chrome is just pure cynicism. Mozilla having to earn money somehow (1% donations!) and Google trying to maximize profits at all costs is not the same thing, even if it might look similar sometimes.
AFAIK, just that it isn't fully open source. It is source available however, but that's not the same. It's sad that they dont go through with it as Vivaldi is by far the most feature rich browser out there.