The high production value of traditional HollyWood productions are only sustainable due to their mass cultural appeal. The problem is that mass culture is in fact, losing mass. These tech giants appear to have misread the signs of this pending sea change and interpret behaviors such as cord-cutting among younger generations to mean they are merely moving their consumption online and that their consumption habits remain otherwise unchanged. One only has to look at the popularity of services like YouTube and Twitch with Gen Z to see that this is in fact not the case. Younger millenials and Gen Z as a whole have completely changed their consumption habits to prefer niche content made by individual creators (or at most a small group) on the cheap. While YouTube stars like PewDiePie cannot be said to be "niche" due to the simple fact that his content captures more eyeballs per year than literally anything else by an enormous margin, the content itself isn't exactly something that appeals to a universal audience in the way that a traditional HollyWood Blockbuster or hit TV show might. Ironically, while Google was the tech giant best positioned to capture the future (at least in terms of how I see it developing), they've severly damaged the future potential of YouTube by playing games with the monwtization and promotion of popular channels while also making it impossible for new creators to make money before they've built their channel into a relative behemoth.
While Apple, Amazon, Disney, et al are throwing massive amounts of capital trying to capture a slice of the streaming service market, they appear to have missed signs of cultural change which will likely cause that market to stagnate over the coming decade. I can't say that trying to create a YouTube competitor is a better idea at this point in time either as that market just isn't large or stable enough at this point in time to say there is even space for a second major servicd for small content creators. I can say the future of entertainment is going to look a lot more like YouTube, where the attention of tens of millions of eyeballs are spread over tens of thousands of channels, rather than a handful of sources for traditional mass media productions.