The problem of all these platforms is that they think they are creating a new market or expanding an existing one and they forget that people only have 24 hours a day to do things.
If you create something like Quibi you're competing with Instagram, Snapchat, TikTok, YouTube, Netflix, Xbox/PlayStation/Nintendo-Switch, Mobile Games and anything else that is trying to grab a slice of you leisure time.
Why would I pay for this when I already pay for other options with more content and get a handful for free?
Quibi is what you get when you think you know your customers but you really don't. It's the type of self-deluded product that is created in an echo chamber by rich people who believe their past success is a formula that can be reproduced at any scale as long as money is involved. The problem with that idea is that it values scale more than ingenuity.
Doing short vertical videos with high production value and charging to watch them is almost an absolute zero in terms of innovation.