Who is this film aimed at? Most OG Trekkies won't watch it, same with most ST:NG, DS9 & Voyager fans that won't watch it and nor will many Enterprise fans. The only people left are the "new" Discovery (and maybe Picard) audience which is very small and definitely not large enough to support a film, even one thats just being streamed, as it won't bring in enough "new" paying fans to cover its costs.
It's just an odd choice with no clear reason to show why it will make enough money for a Studio to say "yes! Lets spend $XXXm on this!!!" that I can see.