with Tubi there’s a very clear answer—it’s owned by Fox Corp, the entity that owns Fox News. they use Tubi to assess media trends and to see what sort of media appeals to people broadly across the political spectrum
the goal is very specifically to gain more long-term viewers for their main cable networks, to capture more of the streaming market, and/ or to cement their market share on news, sports, and streaming markets both in the US and abroad. while they sell user data to third parties they are also using it to conduct their own market research
Fox is currently trying to acquire Roku TV and there’s a movement by Democrat politicians in the US to stop the acquisition because it would give Fox an unfair monopoly on free or advertisement supported streaming in the US
anyways the money is coming from Rupert Murdoch and his major investors wanting to “win the culture war” (or whatever they think gaining a larger audience will do for them both politically and socio culturally)
these extremely rich people are committed to throwing as much random bullshit at the wall to see if it will stick—Tubi is just one facet of their approach